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2.3.1.243

Relevance: 100%

Accepted name:

acyl-Kdo₂-lipid IV_A acyltransferase

Reaction:

a fatty acyl-[acyl-carrier protein] + an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)-[lipid IV_A] = an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)₂-[lipid IV_A] + an [acyl-carrier protein]

For diagram of Kdo-Kdo-Lipid IV_A metabolism, click here

Glossary:

Kdo = 3-deoxy-D-manno-oct-2-ulopyranosylonic acid
a lipid IV_A = 2-deoxy-2-{[(3R)-3-hydroxyacyl]amino}-3-O-[(3R)-3-hydroxyacyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phospho-α-D-glucopyranose
an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)-[lipid IV_A] = 3-deoxy-α-D-manno-oct-2-ulopyranosyl-(2→4)-3-deoxy-α-D-manno-oct-2-ulopyranosyl-(2→6)-2-deoxy-2-{[(3R)-3-(acyloxy)acyl]amino}-3-O-[(3R)-3-hydroxyacyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phosphono-α-D-glucopyranose
an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)₂-[lipid IV_A] = 3-deoxy-α-D-manno-oct-2-ulopyranosyl-(2→4)-3-deoxy-α-D-manno-oct-2-ulopyranosyl-(2→6)-2-deoxy-2-{[(3R)-3-(acyloxy)acyl]amino}-3-O-[(3R)-3-(acyloxy)acyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phospho-α-D-glucopyranose

Other name(s):

lpxM (gene name); MsbB acyltransferase; myristoyl-[acyl-carrier protein]:α-Kdo-(2→4)-α-Kdo-(2→6)-(dodecanoyl)-lipid IV_A O-myristoyltransferase; tetradecanoyl-[acyl-carrier protein]:dodecanoyl-Kdo₂-lipid IV_A O-tetradecanoyltransferase; lauroyl-Kdo₂-lipid IV_A myristoyltransferase

Systematic name:

fatty acyl-[acyl-carrier protein]:α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)-[lipid IV_A] O-acyltransferase

Comments:

The enzyme is involved in the biosynthesis of the phosphorylated outer membrane glycolipid lipid A. It transfers an acyl group to the 3-O position of the 3R-hydroxyacyl already attached at the 2-O position of the non-reducing glucosamine molecule. The enzyme from the bacterium Escherichia coli is specific for myristoyl (C₁₄) acyl groups, giving the enzyme its previous accepted name. However, enzymes from different species accept highly variable substrates.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Clementz, T., Zhou, Z. and Raetz, C.R. Function of the Escherichia coli msbB gene, a multicopy suppressor of htrB knockouts, in the acylation of lipid A. Acylation by MsbB follows laurate incorporation by HtrB. J. Biol. Chem. 272 (1997) 10353–10360. [DOI] [PMID: 9099672]
2.	Dovala, D., Rath, C.M., Hu, Q., Sawyer, W.S., Shia, S., Elling, R.A., Knapp, M.S. and Metzger, L.E., 4th. Structure-guided enzymology of the lipid A acyltransferase LpxM reveals a dual activity mechanism. Proc. Natl. Acad. Sci. USA 113 (2016) E6064–E6071. [DOI] [PMID: 27681620]

[EC 2.3.1.243 created 2014, modified 2021]

2.3.1.241

Relevance: 96.9%

Accepted name:

Kdo₂-lipid IV_A acyltransferase

Reaction:

a fatty acyl-[acyl-carrier protein] + an α-Kdo-(2→4)-α-Kdo-(2→6)-[lipid IV_A] = an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)-[lipid IV_A] + an [acyl-carrier protein]

For diagram of Kdo-Kdo-Lipid IV_A metabolism, click here

Glossary:

Other name(s):

LpxL; htrB (gene name); dodecanoyl-[acyl-carrier protein]:α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IV_A O-dodecanoyltransferase; lauroyl-[acyl-carrier protein]:Kdo₂-lipid IV_A O-lauroyltransferase; (Kdo)₂-lipid IV_A lauroyltransferase; α-Kdo-(2→4)-α-(2→6)-lipid IV_A lauroyltransferase; dodecanoyl-[acyl-carrier protein]:Kdo₂-lipid IV_A O-dodecanoyltransferase; Kdo₂-lipid IV_A lauroyltransferase

Systematic name:

fatty acyl-[acyl-carrier protein]:α-Kdo-(2→4)-α-Kdo-(2→6)-[lipid IV_A] O-acyltransferase

Comments:

The enzyme is involved in the biosynthesis of the phosphorylated outer membrane glycolipid lipid A. It transfers an acyl group to the 3-O position of the 3R-hydroxyacyl already attached to the nitrogen of the non-reducing glucosamine molecule. The enzyme from the bacterium Escherichia coli is specific for lauryl (C₁₂) acyl groups, giving the enzyme its previous accepted name. However, enzymes from different species accept highly variable substrates.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Clementz, T., Bednarski, J.J. and Raetz, C.R. Function of the htrB high temperature requirement gene of Escherichia coli in the acylation of lipid A: HtrB catalyzed incorporation of laurate. J. Biol. Chem. 271 (1996) 12095–12102. [DOI] [PMID: 8662613]
2.	van der Ley, P., Steeghs, L., Hamstra, H.J., ten Hove, J., Zomer, B. and van Alphen, L. Modification of lipid A biosynthesis in Neisseria meningitidis lpxL mutants: influence on lipopolysaccharide structure, toxicity, and adjuvant activity. Infect. Immun. 69 (2001) 5981–5990. [DOI] [PMID: 11553534]
3.	McLendon, M.K., Schilling, B., Hunt, J.R., Apicella, M.A. and Gibson, B.W. Identification of LpxL, a late acyltransferase of Francisella tularensis. Infect. Immun. 75 (2007) 5518–5531. [DOI] [PMID: 17724076]
4.	Six, D.A., Carty, S.M., Guan, Z. and Raetz, C.R. Purification and mutagenesis of LpxL, the lauroyltransferase of Escherichia coli lipid A biosynthesis. Biochemistry 47 (2008) 8623–8637. [DOI] [PMID: 18656959]
5.	Fathy Mohamed, Y., Hamad, M., Ortega, X.P. and Valvano, M.A. The LpxL acyltransferase is required for normal growth and penta-acylation of lipid A in Burkholderia cenocepacia. Mol. Microbiol. 104 (2017) 144–162. [DOI] [PMID: 28085228]

[EC 2.3.1.241 created 2014, modified 2021]

2.3.1.242

Relevance: 80.9%

Accepted name:

Kdo₂-lipid IV_A palmitoleoyltransferase

Reaction:

a (9Z)-hexadec-9-enoyl-[acyl-carrier protein] + Kdo₂-lipid IV_A = (9Z)-hexadec-9-enoyl-Kdo₂-lipid IV_A + an [acyl-carrier protein]

For diagram of Kdo-Kdo-Lipid IV_A metabolism, click here

Glossary:

Kdo = 3-deoxy-D-manno-oct-2-ulopyranosylonic acid
lipid IV_A = 2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl phosphate
Kdo₂-lipid IV_A = α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IV_A
(9Z)-hexadec-9-enoyl = palmitoleoyl
(9Z)-hexadec-9-enoyl-Kdo₂-lipid IV_A = α-Kdo-(2→4)-α-Kdo-(2→6)-2-deoxy-2-{(3R)-3-[(9Z)-hexadec-9-enoyl]tetradecanamido}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl phosphate

Other name(s):

LpxP; palmitoleoyl-acyl carrier protein-dependent acyltransferase; cold-induced palmitoleoyl transferase; palmitoleoyl-[acyl-carrier protein]:Kdo₂-lipid IV_A O-palmitoleoyltransferase; (Kdo)₂-lipid IV_A palmitoleoyltransferase; α-Kdo-(2→4)-α-(2→6)-lipid IV_A palmitoleoyltransferase

Systematic name:

(9Z)-hexadec-9-enoyl-[acyl-carrier protein]:Kdo₂-lipid IV_A O-palmitoleoyltransferase

Comments:

The enzyme, characterized from the bacterium Escherichia coli, is induced upon cold shock and is involved in the formation of a cold-adapted variant of the outer membrane glycolipid lipid A.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Carty, S.M., Sreekumar, K.R. and Raetz, C.R. Effect of cold shock on lipid A biosynthesis in Escherichia coli. Induction At 12 degrees C of an acyltransferase specific for palmitoleoyl-acyl carrier protein. J. Biol. Chem. 274 (1999) 9677–9685. [DOI] [PMID: 10092655]
2.	Vorachek-Warren, M.K., Carty, S.M., Lin, S., Cotter, R.J. and Raetz, C.R. An Escherichia coli mutant lacking the cold shock-induced palmitoleoyltransferase of lipid A biosynthesis: absence of unsaturated acyl chains and antibiotic hypersensitivity at 12 degrees C. J. Biol. Chem. 277 (2002) 14186–14193. [DOI] [PMID: 11830594]

[EC 2.3.1.242 created 2014]

2.7.4.30

Transferred entry:

lipid A phosphoethanolamine transferase. Now EC 2.7.8.43, lipid A phosphoethanolamine transferase

[EC 2.7.4.30 created 2015, deleted 2016]

2.7.8.43

Relevance: 79.9%

Accepted name:

lipid A phosphoethanolamine transferase

Reaction:

(1) diacylphosphatidylethanolamine + lipid A = diacylglycerol + lipid A 1-(2-aminoethyl diphosphate)
(2) diacylphosphatidylethanolamine + lipid A = diacylglycerol + lipid A 4′-(2-aminoethyl diphosphate)
(3) diacylphosphatidylethanolamine + lipid A 1-(2-aminoethyl diphosphate) = diacylglycerol + lipid A 1,4′-bis(2-aminoethyl diphosphate)

Glossary:

lipid A (Campylobacter jejuni) = 2,3-dideoxy-2,3-bis[(3R)-3-(hexadecanoyloxy)tetradecanamido]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl phosphate
lipid A (Escherichia coli) =
2-deoxy-2-[(3R)-3-(tetradecanoyloxy)tetradecanamido]-3-O-[(3R)-3-(dodecanoyloxy)tetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl phosphate
lipid A (Helicobacter pylori) = 2-deoxy-2-[(3R)-3-(octadecanoyloxy)octadecanamido]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyhexadecanoyl]-2-[(3R)-3-hydroxyoctadecanamido]-α-D-glucopyranosyl phosphate
lipid A (Neisseria meningitidis) =
2-deoxy-3-O-[(3R)-3-hydroxydodecanoyl]-2-[(3R)-3-(dodecanoyloxy)tetradecanamido]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxydodecanoyl]-2-[(3R)-3-(dodecanoyloxy)tetradecanamido]-α-D-glucopyranosyl phosphate
lipid A 1-[(2-aminoethyl) diphosphate] = P1-(2-aminoethyl)
P2-(2-deoxy-2-[(3R)-3-(tetradecanoyloxy)tetradecanamido]-3-O-[(3R)-3-(dodecanoyloxy)tetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl) diphosphate
lipid A 1,4′-bis(2-aminoethyl diphosphate) = P1-(2-aminoethyl)
P2-(2-deoxy-2-[(3R)-3-(tetradecanoyloxy)tetradecanamido]-3-O-[(3R)-3-(dodecanoyloxy)tetradecanoyl]-4-O-(2-aminoethyldiphospho)-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl) diphosphate

Other name(s):

lipid A PEA transferase; LptA

Systematic name:

diacylphosphatidylethanolamine:lipid-A ethanolaminephosphotransferase

Comments:

The enzyme adds one or two ethanolamine phosphate groups to lipid A giving a diphosphate, sometimes in combination with EC 2.4.2.43 (lipid IV_A 4-amino-4-deoxy-L-arabinosyltransferase) giving products with 4-amino-4-deoxy-β-L-arabinose groups at the phosphates of lipid A instead of diphosphoethanolamine groups. It will also act on lipid IV_A and Kdo₂-lipid A.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Tran, A.X., Karbarz, M.J., Wang, X., Raetz, C.R., McGrath, S.C., Cotter, R.J. and Trent, M.S. Periplasmic cleavage and modification of the 1-phosphate group of Helicobacter pylori lipid A. J. Biol. Chem. 279 (2004) 55780–55791. [DOI] [PMID: 15489235]
2.	Herrera, C.M., Hankins, J.V. and Trent, M.S. Activation of PmrA inhibits LpxT-dependent phosphorylation of lipid A promoting resistance to antimicrobial peptides. Mol. Microbiol. 76 (2010) 1444–1460. [DOI] [PMID: 20384697]
3.	Cullen, T.W. and Trent, M.S. A link between the assembly of flagella and lipooligosaccharide of the Gram-negative bacterium Campylobacter jejuni. Proc. Natl. Acad. Sci. USA 107 (2010) 5160–5165. [DOI] [PMID: 20194750]
4.	Anandan, A., Piek, S., Kahler, C.M. and Vrielink, A. Cloning, expression, purification and crystallization of an endotoxin-biosynthesis enzyme from Neisseria meningitidis. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 68 (2012) 1494–1497. [DOI] [PMID: 23192031]
5.	Wanty, C., Anandan, A., Piek, S., Walshe, J., Ganguly, J., Carlson, R.W., Stubbs, K.A., Kahler, C.M. and Vrielink, A. The structure of the neisserial lipooligosaccharide phosphoethanolamine transferase A (LptA) required for resistance to polymyxin. J. Mol. Biol. 425 (2013) 3389–3402. [DOI] [PMID: 23810904]

[EC 2.7.8.43 created 2015 as EC 2.7.4.30, transferred 2016 to EC 2.7.8.43]

2.7.4.29

Relevance: 76.3%

Accepted name:

Kdo₂-lipid A phosphotransferase

Reaction:

ditrans-octacis-undecaprenyl diphosphate + α-D-Kdo-(2→4)-α-D-Kdo-(2→6)-lipid A = ditrans-octacis-undecaprenyl phosphate + α-D-Kdo-(2→4)-α-D-Kdo-(2→6)-lipid A 1-diphosphate

Glossary:

lipid A = 2-deoxy-2-[(3R)-3-(tetradecanoyloxy)tetradecanamido]-3-O-[(3R)-3-(dodecanoyloxy)tetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl phosphate
lipid A 1-diphosphate =
2-deoxy-2-[(3R)-3-(tetradecanoyloxy)tetradecanamido]-3-O-[(3R)-3-(dodecanoyloxy)tetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl diphosphate

Other name(s):

lipid A undecaprenyl phosphotransferase; LpxT; YeiU

Systematic name:

ditrans-octacis-undecaprenyl-diphosphate:α-D-Kdo-(2→4)-α-D-Kdo-(2→6)-lipid-A phosphotransferase

Comments:

An inner-membrane protein. The activity of the enzyme is regulated by PmrA. In vitro the enzyme can use diacylglycerol 3-diphosphate as the phosphate donor.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Touze, T., Tran, A.X., Hankins, J.V., Mengin-Lecreulx, D. and Trent, M.S. Periplasmic phosphorylation of lipid A is linked to the synthesis of undecaprenyl phosphate. Mol. Microbiol. 67 (2008) 264–277. [DOI] [PMID: 18047581]
2.	Herrera, C.M., Hankins, J.V. and Trent, M.S. Activation of PmrA inhibits LpxT-dependent phosphorylation of lipid A promoting resistance to antimicrobial peptides. Mol. Microbiol. 76 (2010) 1444–1460. [DOI] [PMID: 20384697]

[EC 2.7.4.29 created 2015]

2.7.8.42

Relevance: 73.6%

Accepted name:

Kdo₂-lipid A phosphoethanolamine 7′′-transferase

Reaction:

(1) diacylphosphatidylethanolamine + α-D-Kdo-(2→4)-α-D-Kdo-(2→6)-lipid A = diacylglycerol + 7-O-[2-aminoethoxy(hydroxy)phosphoryl]-α-D-Kdo-(2→4)-α-D-Kdo-(2→6)-lipid A
(2) diacylphosphatidylethanolamine + α-D-Kdo-(2→4)-α-D-Kdo-(2→6)-lipid IV_A = diacylglycerol + 7-O-[2-aminoethoxy(hydroxy)phosphoryl]-α-D-Kdo-(2→4)-α-D-Kdo-(2→6)-lipid IV_A

Glossary:

lipid A = 2-deoxy-2-[(3R)-3-(tetradecanoyloxy)tetradecanamido]-3-O-[(3R)-3-(dodecanoyloxy)tetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl phosphate
lipid IV_A = 2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl phosphate

Other name(s):

eptB (gene name)

Systematic name:

diacylphosphatidylethanolamine:α-D-Kdo-(2→4)-α-D-Kdo-(2→6)-lipid-A 7′′-phosphoethanolaminetransferase

Comments:

The enzyme has been characterized from the bacterium Escherichia coli. It is activated by Ca²⁺ ions and is silenced by the sRNA MgrR.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Kanipes, M.I., Lin, S., Cotter, R.J. and Raetz, C.R. Ca²⁺-induced phosphoethanolamine transfer to the outer 3-deoxy-D-manno-octulosonic acid moiety of Escherichia coli lipopolysaccharide. A novel membrane enzyme dependent upon phosphatidylethanolamine. J. Biol. Chem. 276 (2001) 1156–1163. [DOI] [PMID: 11042192]
2.	Reynolds, C.M., Kalb, S.R., Cotter, R.J. and Raetz, C.R. A phosphoethanolamine transferase specific for the outer 3-deoxy-D-manno-octulosonic acid residue of Escherichia coli lipopolysaccharide. Identification of the eptB gene and Ca²⁺ hypersensitivity of an eptB deletion mutant. J. Biol. Chem. 280 (2005) 21202–21211. [DOI] [PMID: 15795227]
3.	Moon, K., Six, D.A., Lee, H.J., Raetz, C.R. and Gottesman, S. Complex transcriptional and post-transcriptional regulation of an enzyme for lipopolysaccharide modification. Mol. Microbiol. 89 (2013) 52–64. [DOI] [PMID: 23659637]

[EC 2.7.8.42 created 2015]

2.4.2.43

Relevance: 62.9%

Accepted name:

lipid IV_A 4-amino-4-deoxy-L-arabinosyltransferase

Reaction:

(1) 4-amino-4-deoxy-α-L-arabinopyranosyl ditrans,octacis-undecaprenyl phosphate + α-Kdo-(2→4)-α-Kdo-(2→6)-lipid A = α-Kdo-(2→4)-α-Kdo-(2→6)-[4-P-L-Ara4N]-lipid A + ditrans,octacis-undecaprenyl phosphate
(2) 4-amino-4-deoxy-α-L-arabinopyranosyl ditrans,octacis-undecaprenyl phosphate + lipid IV_A = lipid II_A + ditrans,octacis-undecaprenyl phosphate
(3) 4-amino-4-deoxy-α-L-arabinopyranosyl ditrans,octacis-undecaprenyl phosphate + α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IV_A = 4′-α-L-Ara4N-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IV_A + ditrans,octacis-undecaprenyl phosphate

For diagram of lipid II_A biosynthesis, click here

Glossary:

lipid IV_A = 2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
lipid II_A = 4-amino-4-deoxy-β-L-arabinopyranosyl 2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-α-D-glucopyranosyl phosphate
α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IV_A = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
4′-α-L-Ara4N-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IV_A = 4-amino-4-deoxy-α-L-arabinopyranosyl 2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-phospho-β-D-glucopyranosy-(1→6)-2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-α-D-glucopyranosyl phosphate
lipid A = lipid A of Escherichia coli = 2-deoxy-2-{[(3R)-3-(dodecanoyloxy)tetradecanoyl]amino}-3-O-[(3R)-3-(tetradecanoyloxy)tetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
α-Kdo-(2→4)-α-Kdo-(2→6)-lipid A = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-(dodecanoyloxy)tetradecanoyl]amino}-3-O-[(3R)-3-(tetradecanoyloxy)tetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
α-Kdo-(2→4)-α-Kdo-(2→6)-[4′-P-α-L-Ara4N]-lipid A = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-(dodecanoyloxy)tetradecanoyl]amino}-3-O-[(3R)-3-(tetradecanoyloxy)tetradecanoyl]-4-O-(4-amino-4-deoxy-α-L-arabinopyranosyl)phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose

Other name(s):

undecaprenyl phosphate-α-L-Ara4N transferase; 4-amino-4-deoxy-L-arabinose lipid A transferase; polymyxin resistance protein PmrK; arnT (gene name)

Systematic name:

4-amino-4-deoxy-α-L-arabinopyranosyl ditrans,octacis-undecaprenyl-phosphate:lipid IV_A 4-amino-4-deoxy-L-arabinopyranosyltransferase

Comments:

Integral membrane protein present in the inner membrane of certain Gram negative endobacteria. In strains that do not produce 3-deoxy-D-manno-octulosonic acid (Kdo), the enzyme adds a single arabinose unit to the 1-phosphate moiety of the tetra-acylated lipid A precursor, lipid IV_A. In the presence of a Kdo disaccharide, the enzyme primarily adds an arabinose unit to the 4-phosphate of lipid A molecules. The Salmonella typhimurium enzyme can add arabinose units to both positions.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB

References:

1.	Trent, M.S., Ribeiro, A.A., Lin, S., Cotter, R.J. and Raetz, C.R. An inner membrane enzyme in Salmonella and Escherichia coli that transfers 4-amino-4-deoxy-L-arabinose to lipid A: induction on polymyxin-resistant mutants and role of a novel lipid-linked donor. J. Biol. Chem. 276 (2001) 43122–43131. [DOI] [PMID: 11535604]
2.	Trent, M.S., Ribeiro, A.A., Doerrler, W.T., Lin, S., Cotter, R.J. and Raetz, C.R. Accumulation of a polyisoprene-linked amino sugar in polymyxin-resistant Salmonella typhimurium and Escherichia coli: structural characterization and transfer to lipid A in the periplasm. J. Biol. Chem. 276 (2001) 43132–43144. [DOI] [PMID: 11535605]
3.	Zhou, Z., Ribeiro, A.A., Lin, S., Cotter, R.J., Miller, S.I. and Raetz, C.R. Lipid A modifications in polymyxin-resistant Salmonella typhimurium: PMRA-dependent 4-amino-4-deoxy-L-arabinose, and phosphoethanolamine incorporation. J. Biol. Chem. 276 (2001) 43111–43121. [DOI] [PMID: 11535603]
4.	Bretscher, L.E., Morrell, M.T., Funk, A.L. and Klug, C.S. Purification and characterization of the L-Ara4N transferase protein ArnT from Salmonella typhimurium. Protein Expr. Purif. 46 (2006) 33–39. [DOI] [PMID: 16226890]
5.	Impellitteri, N.A., Merten, J.A., Bretscher, L.E. and Klug, C.S. Identification of a functionally important loop in Salmonella typhimurium ArnT. Biochemistry 49 (2010) 29–35. [DOI] [PMID: 19947657]

[EC 2.4.2.43 created 2010, modified 2011]

3.1.2.21

Relevance: 59.1%

Accepted name:

dodecanoyl-[acyl-carrier-protein] hydrolase

Reaction:

a dodecanoyl-[acyl-carrier protein] + H₂O = an [acyl-carrier protein] + dodecanoate

Other name(s):

lauryl-acyl-carrier-protein hydrolase; dodecanoyl-acyl-carrier-protein hydrolase; dodecyl-acyl-carrier protein hydrolase; dodecanoyl-[acyl-carrier protein] hydrolase; dodecanoyl-[acyl-carrier-protein] hydrolase

Systematic name:

dodecanoyl-[acyl-carrier protein] hydrolase

Comments:

Acts on the acyl-carrier-protein thioester of C₁₂ and, with a much lower activity, C₁₄ fatty acids. The derivative of oleic acid is hydrolysed very slowly (cf. EC 3.1.2.14, oleoyl-[acyl-carrier-protein] hydrolase).

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 137903-37-8

References:

1.	Pollard, M.R., Anderson, L., Fan, C., Hawkins, D.J., Davies, H.M. A specific acyl-ACP thioesterase implicated in medium-chain fatty acid production in immature cotyledons of Umbellularia californica. Arch. Biochem. Biophys. 284 (1991) 306–312. [DOI] [PMID: 1989513]
2.	Davies, H.M., Anderson, L., Fan, C., Hawkins, D.J. Developmental induction, purification, and further characterization of 12:0-ACP thioesterase from immature cotyledons of Umbellularia californica. Arch. Biochem. Biophys. 290 (1991) 37–45. [DOI] [PMID: 1898097]

[EC 3.1.2.21 created 1999]

2.3.1.251

Relevance: 54.3%

Accepted name:

lipid IV_A palmitoyltransferase

Reaction:

(1) 1-palmitoyl-2-acyl-sn-glycero-3-phosphocholine + hexa-acyl lipid A = 2-acyl-sn-glycero-3-phosphocholine + hepta-acyl lipid A
(2) 1-palmitoyl-2-acyl-sn-glycero-3-phosphocholine + lipid II_A = 2-acyl-sn-glycero-3-phosphocholine + lipid II_B
(3) 1-palmitoyl-2-acyl-sn-glycero-3-phosphocholine + lipid IV_A = 2-acyl-sn-glycero-3-phosphocholine + lipid IV_B

For diagram of lipid IV_B biosynthesis, click here

Glossary:

palmitoyl = hexadecanoyl
hexa-acyl lipid A = 2-deoxy-2-[(3R)-3-(tetradecanoyloxy)tetradecanamido]-3-O-[(3R)-3-(dodecanoyloxy)tetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl phosphate
hepta-acyl lipid A = 2-deoxy-2-[(3R)-3-(tetradecanoyloxy)tetradecanamido]-3-O-[(3R)-3-(dodecanoyloxy)tetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-(hexadecanoyloxy)tetradecanamido]-α-D-glucopyranosyl phosphate
lipid II_A = 4-amino-4-deoxy-β-L-arabinopyranosyl 2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranose phosphate
lipid II_B = 4-amino-4-deoxy-β-L-arabinopyranosyl 2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-(hexadecanoyloxy)tetradecanamido]-α-D-glucopyranosyl phosphate
lipid IV_A = 2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranose phosphate
lipid IV_B = 2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-(hexadecanoyloxy)tetradecanamido]-α-D-glucopyranosyl phosphate

Other name(s):

PagP; crcA (gene name)

Systematic name:

1-palmitoyl-2-acyl-sn-glycero-3-phosphocholine:lipid-IV_A palmitoyltransferase

Comments:

Isolated from the bacteria Escherichia coli and Salmonella typhimurium. The enzyme prefers phosphatidylcholine with a palmitoyl group at the sn-1 position and palmitoyl or stearoyl groups at the sn-2 position. There is some activity with corresponding phosphatidylserines but only weak activity with other diacylphosphatidyl compounds. The enzyme also acts on Kdo-(2→4)-Kdo-(2→6)-lipid IV_A.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB

References:

1.	Bishop, R.E., Gibbons, H.S., Guina, T., Trent, M.S., Miller, S.I. and Raetz, C.R. Transfer of palmitate from phospholipids to lipid A in outer membranes of gram-negative bacteria. EMBO J. 19 (2000) 5071–5080. [DOI] [PMID: 11013210]
2.	Cuesta-Seijo, J.A., Neale, C., Khan, M.A., Moktar, J., Tran, C.D., Bishop, R.E., Pomes, R. and Prive, G.G. PagP crystallized from SDS/cosolvent reveals the route for phospholipid access to the hydrocarbon ruler. Structure 18 (2010) 1210–1219. [DOI] [PMID: 20826347]

[EC 2.3.1.251 created 2015]

2.3.3.4

Relevance: 53.2%

Accepted name:

decylhomocitrate synthase

Reaction:

dodecanoyl-CoA + H₂O + 2-oxoglutarate = (3S,4S)-3-hydroxytetradecane-1,3,4-tricarboxylate + CoA

For diagram of reaction, click here

Other name(s):

2-decylhomocitrate synthase; 3-hydroxytetradecane-1,3,4-tricarboxylate 2-oxoglutarate-lyase (CoA-acylating)

Systematic name:

dodecanoyl-CoA:2-oxoglutarate C-dodecanoyltransferase (thioester-hydrolysing, 1-carboxyundecyl-forming)

Comments:

Decanoyl-CoA can act instead of dodecanoyl-CoA, but 2-oxoglutarate cannot be replaced by oxaloacetate or pyruvate.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 51845-40-0

References:

1.	Maahlén, A. Purification and some properties of 2-decylhomocitrate synthase from Penicillium spiculisporum. Eur. J. Biochem. 38 (1973) 32–39. [DOI] [PMID: 4774124]
2.	Brandäge, S., Dahlman, O., Lindqvist, B., Maahlén, A. and Mörch, L. Absolute configuration and enantiospecific synthesis of spiculisporic acid. Acta Chem. Scand. 38B (1984) 837–844.

[EC 2.3.3.4 created 1976 as EC 4.1.3.29, transferred 2002 to EC 2.3.3.4]

2.3.1.97

Relevance: 43.5%

Accepted name:

glycylpeptide N-tetradecanoyltransferase

Reaction:

tetradecanoyl-CoA + an N-terminal-glycyl-[protein] = CoA + an N-terminal-N-tetradecanoylglycyl-[protein]

Glossary:

tetradecanoyl-CoA = myristoyl-CoA

Other name(s):

NMT (gene name); peptide N-myristoyltransferase; myristoyl-CoA-protein N-myristoyltransferase; myristoyl-coenzyme A:protein N-myristoyl transferase; myristoylating enzymes; protein N-myristoyltransferase; tetradecanoyl-CoA:glycylpeptide N-tetradecanoyltransferase

Systematic name:

tetradecanoyl-CoA:N-terminal-glycine-[protein] N-tetradecanoyltransferase

Comments:

The enzyme catalyses the transfer of myristic acid from myristoyl-CoA to the amino group of the N-terminal glycine residue in a variety of eukaryotic proteins. It uses an ordered Bi Bi reaction in which myristoyl-CoA binds to the enzyme prior to the binding of the peptide substrate, and CoA release precedes the release of the myristoylated peptide. The enzyme from yeast is profoundly affected by amino acids further from the N-terminus, and is particularly stimulated by a serine residue at position 5.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 110071-61-9

References:

1.	Guertin, D., Gris-Miron, L. and Riendeau, D. Identification of a 51-kilodalton polypeptide fatty acyl chain acceptor in soluble extracts from mouse cardiac tissue. Biochem. Cell Biol. 64 (1986) 1249–1255. [PMID: 3566958]
2.	Heuckeroth, R.O., Towler, D.A., Adams, S.P., Glaser, L. and Gordon, J.I. 11-(Ethylthio)undecanoic acid. A myristic acid analogue of altered hydrophobicity which is functional for peptide N-myristoylation with wheat germ and yeast acyltransferase. J. Biol. Chem. 263 (1988) 2127–2133. [PMID: 3123489]
3.	Towler, D.A., Adams, S.P., Eubanks, S.R., Towery, D.S., Jackson-Machelski, E., Glaser, L. and Gordon, J.I. Purification and characterization of yeast myristoyl CoA:protein N-myristoyltransferase. Proc. Natl. Acad. Sci. USA 84 (1987) 2708–2712. [PMID: 3106975]
4.	McIlhinney, R.A., Young, K., Egerton, M., Camble, R., White, A. and Soloviev, M. Characterization of human and rat brain myristoyl-CoA:protein N-myristoyltransferase: evidence for an alternative splice variant of the enzyme. Biochem. J. 333 (1998) 491–495. [PMID: 9677304]
5.	Farazi, T.A., Waksman, G. and Gordon, J.I. Structures of Saccharomyces cerevisiae N-myristoyltransferase with bound myristoylCoA and peptide provide insights about substrate recognition and catalysis. Biochemistry 40 (2001) 6335–6343. [PMID: 11371195]

[EC 2.3.1.97 created 1989, modified 1990, modified 2018]

2.1.1.344

Relevance: 42.8%

Accepted name:

ornithine lipid N-methyltransferase

Reaction:

3 S-adenosyl-L-methionine + an ornithine lipid = 3 S-adenosyl-L-homocysteine + an N,N,N-trimethylornithine lipid (overall reaction)
(1a) S-adenosyl-L-methionine + an ornithine lipid = S-adenosyl-L-homocysteine + an N-methylornithine lipid
(1b) S-adenosyl-L-methionine + an N-methylornithine lipid = S-adenosyl-L-homocysteine + an N,N-dimethylornithine lipid
(1c) S-adenosyl-L-methionine + an N,N-dimethylornithine lipid = S-adenosyl-L-homocysteine + an N,N,N-trimethylornithine lipid

Glossary:

an ornithine lipid = an N^α-[(3R)-3-(acyloxy)acyl]-L-ornithine

Other name(s):

olsG (gene name)

Systematic name:

S-adenosyl-L-methionine:ornithine lipid N-methyltransferase

Comments:

The enzyme, characterized from the bacterium Singulisphaera acidiphila, catalyses three successive methylations of the terminal δ-nitrogen in ornithine lipids.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

Escobedo-Hinojosa, W.I., Vences-Guzman, M.A., Schubotz, F., Sandoval-Calderon, M., Summons, R.E., Lopez-Lara, I.M., Geiger, O. and Sohlenkamp, C. OlsG (Sinac_1600) is an ornithine lipid N-methyltransferase from the planctomycete Singulisphaera acidiphila. J. Biol. Chem. 290 (2015) 15102–15111. [DOI] [PMID: 25925947]

[EC 2.1.1.344 created 2017]

1.14.99.32

Transferred entry:

myristoyl-CoA 11-(Z) desaturase. Now classified as EC 1.14.19.5, acyl-CoA 11-(Z)-desaturase.

[EC 1.14.99.32 created 2000, deleted 2015]

2.3.1.301

Relevance: 38.1%

Accepted name:

mycobacterial β-ketoacyl-[acyl carrier protein] synthase III

Reaction:

dodecanoyl-CoA + a malonyl-[acyl-carrier protein] = a 3-oxotetradecanoyl-[acyl-carrier protein] + CoA + CO₂

Glossary:

dodecanoyl-CoA = lauroyl-CoA

Other name(s):

fabH (gene name) (ambiguous); mycobacterial 3-oxoacyl-[acyl carrier protein] synthase III

Systematic name:

dodecanoyl-CoA:malonyl-[acyl-carrier protein] C-acyltransferase

Comments:

The enzyme, characterized from mycobacteria, provides a link between the type I and type II fatty acid synthase systems (FAS-I and FAS-II, respectively) found in these organisms. The enzyme acts on medium- and long-chain acyl-CoAs (C₁₂-C₁₆) produced by the FAS-I system, condensing them with malonyl-[acyl-carrier protein] (malonyl-AcpM) and forming starter molecules for the FAS-II system, which elongates them into meromycolic acids. The enzyme has no activity with short-chain acyl-CoAs (e.g. acetyl-CoA), which are used by EC 2.3.1.180, β-ketoacyl-[acyl-carrier-protein] synthase III, or branched-chain acyl-CoAs, which are used by EC 2.3.1.300, branched-chain β-ketoacyl-[acyl-carrier-protein] synthase.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Scarsdale, J.N., Kazanina, G., He, X., Reynolds, K.A. and Wright, H.T. Crystal structure of the Mycobacterium tuberculosis β-ketoacyl-acyl carrier protein synthase III. J. Biol. Chem. 276 (2001) 20516–20522. [DOI] [PMID: 11278743]
2.	Musayev, F., Sachdeva, S., Scarsdale, J.N., Reynolds, K.A. and Wright, H.T. Crystal structure of a substrate complex of Mycobacterium tuberculosis β-ketoacyl-acyl carrier protein synthase III (FabH) with lauroyl-coenzyme A. J. Mol. Biol. 346 (2005) 1313–1321. [DOI] [PMID: 15713483]
3.	Brown, A.K., Sridharan, S., Kremer, L., Lindenberg, S., Dover, L.G., Sacchettini, J.C. and Besra, G.S. Probing the mechanism of the Mycobacterium tuberculosis β-ketoacyl-acyl carrier protein synthase III mtFabH: factors influencing catalysis and substrate specificity. J. Biol. Chem. 280 (2005) 32539–32547. [DOI] [PMID: 16040614]
4.	Sachdeva, S., Musayev, F.N., Alhamadsheh, M.M., Scarsdale, J.N., Wright, H.T. and Reynolds, K.A. Separate entrance and exit portals for ligand traffic in Mycobacterium tuberculosis FabH. Chem. Biol. 15 (2008) 402–412. [DOI] [PMID: 18420147]

[EC 2.3.1.301 created 2021]

1.14.11.58

Relevance: 36.2%

Accepted name:

ornithine lipid ester-linked acyl 2-hydroxylase

Reaction:

an ornithine lipid + 2-oxoglutarate + O₂ = a 2-hydroxyornithine lipid + succinate + CO₂

Glossary:

an ornithine lipid = an N^α-[(3R)-3-(acyloxy)acyl]-L-ornithine
a 2-hydroxyornithine lipid = an N^α-[(3R)-3-(2-hydroxyacyloxy)acyl]-L-ornithine

Other name(s):

olsC (gene name)

Systematic name:

ornithine lipid,2-oxoglutarate:oxygen oxidoreductase (ester-linked acyl 2-hydroxylase)

Comments:

The enzyme, characterized from the bacterium Rhizobium tropici, catalyses the hydroxylation of C-2 of the fatty acyl group that is ester-linked to the 3-hydroxy position of the amide-linked fatty acid.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Rojas-Jimenez, K., Sohlenkamp, C., Geiger, O., Martinez-Romero, E., Werner, D. and Vinuesa, P. A ClC chloride channel homolog and ornithine-containing membrane lipids of Rhizobium tropici CIAT899 are involved in symbiotic efficiency and acid tolerance. Mol. Plant Microbe Interact. 18 (2005) 1175–1185. [DOI] [PMID: 16353552]
2.	Vences-Guzman, M.A., Guan, Z., Ormeno-Orrillo, E., Gonzalez-Silva, N., Lopez-Lara, I.M., Martinez-Romero, E., Geiger, O. and Sohlenkamp, C. Hydroxylated ornithine lipids increase stress tolerance in Rhizobium tropici CIAT899. Mol. Microbiol. 79 (2011) 1496–1514. [DOI] [PMID: 21205018]

[EC 1.14.11.58 created 2018]

2.7.1.235

Relevance: 35.8%

Accepted name:

lipopolysaccharide core heptose(I) kinase

Reaction:

ATP + an α-Hep-(1→3)-α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A] = ADP + an α-Hep-(1→3)-4-O-phospho-α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A]

Glossary:

Lipid A is a lipid component of the lipopolysaccharides (LPS) of Gram-negative bacteria. It usually consists of two glucosamine units connected by a β(1→6) bond and decorated with four to seven acyl chains and up to two phosphate groups.
Hep = L-glycero-β-D-manno-heptose

Other name(s):

WaaP; RfaP

Systematic name:

ATP:an α-Hep-(1→3)-α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A] heptose^I 4-O-phosphotransferase

Comments:

The enzyme catalyses the phosphorylation of L-glycero-D-manno-heptose I (the first heptose added to the lipid, Hep I) in the biosynthesis of the inner core oligosaccharide of the lipopolysaccharide (endotoxin) of some Gram-negative bacteria.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Yethon, J.A. and Whitfield, C. Purification and characterization of WaaP from Escherichia coli, a lipopolysaccharide kinase essential for outer membrane stability. J. Biol. Chem. 276 (2001) 5498–5504. [DOI] [PMID: 11069912]
2.	Zhao, X. and Lam, J.S. WaaP of Pseudomonas aeruginosa is a novel eukaryotic type protein-tyrosine kinase as well as a sugar kinase essential for the biosynthesis of core lipopolysaccharide. J. Biol. Chem. 277 (2002) 4722–4730. [DOI] [PMID: 11741974]
3.	Kreamer, N.NK., Chopra, R., Caughlan, R.E., Fabbro, D., Fang, E., Gee, P., Hunt, I., Li, M., Leon, B.C., Muller, L., Vash, B., Woods, A.L., Stams, T., Dean, C.R. and Uehara, T. Acylated-acyl carrier protein stabilizes the Pseudomonas aeruginosa WaaP lipopolysaccharide heptose kinase. Sci. Rep. 8:14124 (2018). [DOI] [PMID: 30237436]

[EC 2.7.1.235 created 2021]

2.7.1.130

Relevance: 35%

Accepted name:

tetraacyldisaccharide 4′-kinase

Reaction:

ATP + a lipid A disaccharide = ADP + a lipid IV_A

For diagram of lipid IV_A biosynthesis, click here

Glossary:

a lipid A disaccharide = a dephospho-lipid IV_A = 2-deoxy-2-{[(3R)-3-hydroxyacyl]amino}-3-O-[(3R)-3-hydroxyacyl]-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phospho-α-D-glucopyranose
a lipid IV_A = 2-deoxy-2-{[(3R)-3-hydroxyacyl]amino}-3-O-[(3R)-3-hydroxyacyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phospho-α-D-glucopyranose

Other name(s):

lpxK (gene name); lipid-A 4′-kinase; ATP:2,2′,3,3′-tetrakis[(3R)-3-hydroxytetradecanoyl]-β-D-glucosaminyl-(1→6)-α-D-glucosaminyl-phosphate 4′-O-phosphotransferase

Systematic name:

ATP:2-deoxy-2-{[(3R)-3-hydroxyacyl]amino}-3-O-[(3R)-3-hydroxyacyl]-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phospho-α-D-glucopyranose 4′-O-phosphotransferase

Comments:

Involved with EC 2.3.1.129 (acyl-[acyl-carrier-protein]—UDP-N-acetylglucosamine O-acyltransferase) and EC 2.4.1.182 (lipid-A-disaccharide synthase) in the biosynthesis of the phosphorylated glycolipid, lipid A, in the outer membrane of Gram-negative bacteria.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 107309-06-8

References:

1.	Ray, B.L. and Raetz, C.R.H. The biosynthesis of gram-negative endotoxin. A novel kinase in Escherichia coli membranes that incorporates the 4′-phosphate of lipid A. J. Biol. Chem. 262 (1987) 1122–1128. [PMID: 3027079]
2.	Emptage, R.P., Daughtry, K.D., Pemble, C.W., 4th and Raetz, C.R. Crystal structure of LpxK, the 4′-kinase of lipid A biosynthesis and atypical P-loop kinase functioning at the membrane interface. Proc. Natl. Acad. Sci. USA 109 (2012) 12956–12961. [DOI] [PMID: 22826246]
3.	Emptage, R.P., Pemble, C.W., 4th, York, J.D., Raetz, C.R. and Zhou, P. Mechanistic characterization of the tetraacyldisaccharide-1-phosphate 4′-kinase LpxK involved in lipid A biosynthesis. Biochemistry 52 (2013) 2280–2290. [DOI] [PMID: 23464738]
4.	Emptage, R.P., Tonthat, N.K., York, J.D., Schumacher, M.A. and Zhou, P. Structural basis of lipid binding for the membrane-embedded tetraacyldisaccharide-1-phosphate 4′-kinase LpxK. J. Biol. Chem. 289 (2014) 24059–24068. [DOI] [PMID: 25023290]

[EC 2.7.1.130 created 1990, modified 2021]

7.5.2.6

Relevance: 34.9%

Accepted name:

ABC-type lipid A-core oligosaccharide transporter

Reaction:

ATP + H₂O + lipid A-core oligosaccharide_{[side 1]} = ADP + phosphate + lipid A-core oligosaccharide_{[side 2]}

Other name(s):

MsbA; lipid flippase; ATP-dependent lipid A-core flippase

Systematic name:

ATP phosphohydrolase (ABC-type, lipid A-core oligosaccharide-translocating)

Comments:

An ATP-binding cassette (ABC) type transporter, characterized by the presence of two similar ATP-binding domains/proteins and two integral membrane domains/proteins. The enzyme, best characterized from the bacterium Escherichia coli, is located in the inner membrane and mediates the movement of lipid A attached to the core oligosaccharide from the cytoplasm to the periplasmic side of the inner membrane, an important step in the lipopolysaccharide biosynthetic pathway. Not to be confused with EC 7.5.2.5, ABC-type lipopolysaccharide transporter (LptB), which is implicated in the translocation of LPS from the inner membrane to the outer membrane and acts later in the process.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB

References:

1.	Karow, M. and Georgopoulos, C. The essential Escherichia coli msbA gene, a multicopy suppressor of null mutations in the htrB gene, is related to the universally conserved family of ATP-dependent translocators. Mol. Microbiol. 7 (1993) 69–79. [PMID: 8094880]
2.	Zhou, Z., White, K.A., Polissi, A., Georgopoulos, C. and Raetz, C.R. Function of Escherichia coli MsbA, an essential ABC family transporter, in lipid A and phospholipid biosynthesis. J. Biol. Chem. 273 (1998) 12466–12475. [PMID: 9575204]
3.	Singh, H., Velamakanni, S., Deery, M.J., Howard, J., Wei, S.L. and van Veen, H.W. ATP-dependent substrate transport by the ABC transporter MsbA is proton-coupled. Nat. Commun. 7:12387 (2016). [PMID: 27499013]

[EC 7.5.2.6 created 2018]

2.4.99.12

Relevance: 34.7%

Accepted name:

lipid IV_A 3-deoxy-D-manno-octulosonic acid transferase

Reaction:

CMP-β-Kdo + a lipid IV_A + CMP-β-Kdo = CMP + an α-Kdo-(2→6)-[lipid IV_A]

For diagram of Kdo₄-Lipid IV_A biosynthesis, click here

Glossary:

CMP-β-Kdo = CMP-3-deoxy-β-D-manno-octulosonate = CMP-3-deoxy-β-D-manno-oct-2-ulopyranosylonate
a lipid IV_A = 2-deoxy-2-{[(3R)-3-hydroxyacyl]amino}-3-O-[(3R)-3-hydroxyacyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phospho-α-D-glucopyranose

Other name(s):

waaA (gene name); kdtA (gene name); 3-deoxy-D-manno-oct-2-ulosonic acid transferase; 3-deoxy-manno-octulosonic acid transferase; lipid IV_A KDO transferase; CMP-3-deoxy-D-manno-oct-2-ulosonate:lipid IV_A 3-deoxy-D-manno-oct-2-ulosonate transferase; KDO transferase

Systematic name:

CMP-3-deoxy-β-D-manno-oct-2-ulosonate:[lipid IV_A] 3-deoxy-D-manno-oct-2-ulosonate transferase (configuration-inverting)

Comments:

The enzyme from Escherichia coli is bifunctional and transfers two 3-deoxy-D-manno-oct-2-ulosonate residues to lipid IV_A (cf. EC 2.4.99.13 [(Kdo)-lipid IV_A 3-deoxy-D-manno-octulosonic acid transferase]) [1]. The monofunctional enzymes from Bordetella pertusis, Aquifex aeolicus and Haemophilus influenzae catalyse the transfer of a single 3-deoxy-D-manno-oct-2-ulosonate residue from CMP-3-deoxy-D-manno-oct-2-ulosonate to lipid IV_A [2-4]. The enzymes from Chlamydia transfer three or more 3-deoxy-D-manno-oct-2-ulosonate residues and generate genus-specific epitopes [5].

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB

References:

1.	Belunis, C.J. and Raetz, C.R. Biosynthesis of endotoxins. Purification and catalytic properties of 3-deoxy-D-manno-octulosonic acid transferase from Escherichia coli. J. Biol. Chem. 267 (1992) 9988–9997. [PMID: 1577828]
2.	Isobe, T., White, K.A., Allen, A.G., Peacock, M., Raetz, C.R. and Maskell, D.J. Bordetella pertussis waaA encodes a monofunctional 2-keto-3-deoxy-D-manno-octulosonic acid transferase that can complement an Escherichia coli waaA mutation. J. Bacteriol. 181 (1999) 2648–2651. [DOI] [PMID: 10198035]
3.	Mamat, U., Schmidt, H., Munoz, E., Lindner, B., Fukase, K., Hanuszkiewicz, A., Wu, J., Meredith, T.C., Woodard, R.W., Hilgenfeld, R., Mesters, J.R. and Holst, O. WaaA of the hyperthermophilic bacterium Aquifex aeolicus is a monofunctional 3-deoxy-D-manno-oct-2-ulosonic acid transferase involved in lipopolysaccharide biosynthesis. J. Biol. Chem. 284 (2009) 22248–22262. [DOI] [PMID: 19546212]
4.	White, K.A., Kaltashov, I.A., Cotter, R.J. and Raetz, C.R. A mono-functional 3-deoxy-D-manno-octulosonic acid (Kdo) transferase and a Kdo kinase in extracts of Haemophilus influenzae. J. Biol. Chem. 272 (1997) 16555–16563. [DOI] [PMID: 9195966]
5.	Lobau, S., Mamat, U., Brabetz, W. and Brade, H. Molecular cloning, sequence analysis, and functional characterization of the lipopolysaccharide biosynthetic gene kdtA encoding 3-deoxy-α-D-manno-octulosonic acid transferase of Chlamydia pneumoniae strain TW-183. Mol. Microbiol. 18 (1995) 391–399. [DOI] [PMID: 8748024]

[EC 2.4.99.12 created 2010, modified 2011]

2.3.1.270

Relevance: 34.7%

Accepted name:

lyso-ornithine lipid O-acyltransferase

Reaction:

a lyso-ornithine lipid + an acyl-[acyl-carrier protein] = an ornithine lipid + a holo-[acyl-carrier protein]

Glossary:

a lyso-ornithine lipid = an N^α-[(3R)-3-hydroxyacyl]-L-ornithine
an ornithine lipid = an N^α-[(3R)-3-(acyloxy)acyl]-L-ornithine

Other name(s):

olsA (gene name)

Systematic name:

N^α-[(3R)-hydroxy-acyl]-L-ornithine O-acyltransferase

Comments:

This bacterial enzyme catalyses the second step in the formation of ornithine lipids.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Weissenmayer, B., Gao, J.L., Lopez-Lara, I.M. and Geiger, O. Identification of a gene required for the biosynthesis of ornithine-derived lipids. Mol. Microbiol. 45 (2002) 721–733. [PMID: 12139618]
2.	Aygun-Sunar, S., Bilaloglu, R., Goldfine, H. and Daldal, F. Rhodobacter capsulatus OlsA is a bifunctional enzyme active in both ornithine lipid and phosphatidic acid biosynthesis. J. Bacteriol. 189 (2007) 8564–8574. [PMID: 17921310]
3.	Lewenza, S., Falsafi, R., Bains, M., Rohs, P., Stupak, J., Sprott, G.D. and Hancock, R.E. The olsA gene mediates the synthesis of an ornithine lipid in Pseudomonas aeruginosa during growth under phosphate-limiting conditions, but is not involved in antimicrobial peptide susceptibility. FEMS Microbiol. Lett. 320 (2011) 95–102. [DOI] [PMID: 21535098]

[EC 2.3.1.270 created 2018]

2.4.99.13

Relevance: 34.4%

Accepted name:

(Kdo)-lipid IV_A 3-deoxy-D-manno-octulosonic acid transferase

Reaction:

CMP-β-Kdo + an α-Kdo-(2→6)-[lipid IV_A] = CMP + an α-Kdo-(2→4)-α-Kdo-(2→6)-[lipid IV_A]

For diagram of Kdo₄-Lipid IV_A biosynthesis, click here

Glossary:

CMP-β-Kdo = CMP-3-deoxy-β-D-manno-oct-2-ulopyranosylonate
a lipid IV_A = 2-deoxy-2-{[(3R)-3-hydroxyacyl]amino}-3-O-[(3R)-3-hydroxyacyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phospho-α-D-glucopyranose

Other name(s):

waaA (gene name); kdtA (gene name); 3-deoxy-D-manno-oct-2-ulosonic acid transferase; 3-deoxy-manno-octulosonic acid transferase; (KDO)-lipid IV_A 3-deoxy-D-manno-octulosonic acid transferase; CMP-3-deoxy-D-manno-oct-2-ulosonate:(Kdo)-lipid IV_A 3-deoxy-D-manno-oct-2-ulosonate transferase; Kdo transferase (ambiguous)

Systematic name:

CMP-3-deoxy-β-D-manno-oct-2-ulosonate:α-Kdo-(2→6)-[lipid IV_A] 3-deoxy-D-manno-oct-2-ulosonate transferase (configuration-inverting)

Comments:

The enzyme from Escherichia coli is bifunctional and transfers two 3-deoxy-D-manno-oct-2-ulosonate residues to lipid IV_A (cf. EC 2.4.99.12 [lipid IV_A 3-deoxy-D-manno-octulosonic acid transferase]) [1]. The enzymes from Chlamydia transfer three or more 3-deoxy-D-manno-oct-2-ulosonate residues and generate genus-specific epitopes [2].

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Belunis, C.J. and Raetz, C.R. Biosynthesis of endotoxins. Purification and catalytic properties of 3-deoxy-D-manno-octulosonic acid transferase from Escherichia coli. J. Biol. Chem. 267 (1992) 9988–9997. [PMID: 1577828]
2.	Lobau, S., Mamat, U., Brabetz, W. and Brade, H. Molecular cloning, sequence analysis, and functional characterization of the lipopolysaccharide biosynthetic gene kdtA encoding 3-deoxy-α-D-manno-octulosonic acid transferase of Chlamydia pneumoniae strain TW-183. Mol. Microbiol. 18 (1995) 391–399. [DOI] [PMID: 8748024]
3.	Schmidt, H., Hansen, G., Singh, S., Hanuszkiewicz, A., Lindner, B., Fukase, K., Woodard, R.W., Holst, O., Hilgenfeld, R., Mamat, U. and Mesters, J.R. Structural and mechanistic analysis of the membrane-embedded glycosyltransferase WaaA required for lipopolysaccharide synthesis. Proc. Natl. Acad. Sci. USA 109 (2012) 6253–6258. [DOI] [PMID: 22474366]

[EC 2.4.99.13 created 2010, modified 2011, modified 2021]

2.4.1.182

Relevance: 34.2%

Accepted name:

lipid-A-disaccharide synthase

Reaction:

a UDP-2-N,3-O-bis[(3R)-3-hydroxyacyl]-α-D-glucosamine + a lipid X = UDP + a lipid A disaccharide

For diagram of lipid IV_A biosynthesis, click here

Glossary:

a lipid X = 2-N-[(3R)-3-hydroxyacyl]-3-O-[(3R)-3-hydroxyacyl]-α-D-glucosamine 1-phosphate =
2-N,3-O-bis[(3R)-3-hydroxyacyl]-α-D-glucosamine
a lipid A disaccharide = a 2-deoxy-2-{[(3R)-3-hydroxyacyl]amino}-3-O-[(3R)-3-hydroxyacyl]-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phospho-α-D-glucopyranose

Other name(s):

lpxB (gene name); UDP-2,3-bis(3-hydroxytetradecanoyl)glucosamine:2,3-bis-(3-hydroxytetradecanoyl)-β-D-glucosaminyl-1-phosphate 2,3-bis(3-hydroxytetradecanoyl)-glucosaminyltransferase (incorrect)

Systematic name:

UDP-2-N,3-O-bis[(3R)-3-hydroxyacyl]-α-D-glucosamine:2-N,3-O-bis[(3R)-3-hydroxyacyl]-α-D-glucosamine 1-phosphate 2-N,3-O-bis[(3R)-3-hydroxyacyl]-α-D-glucosaminyltransferase

Comments:

Involved with EC 2.3.1.129 (acyl-[acyl-carrier-protein]—UDP-N-acetylglucosamine O-acyltransferase) and EC 2.7.1.130 (tetraacyldisaccharide 4′-kinase) in the biosynthesis of the phosphorylated glycolipid, lipid A, in the outer membrane of Gram-negative bacteria.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 105843-81-0

References:

1.	Ray, B.L., Painter, G. and Raetz, C.R.H. The biosynthesis of gram-negative endotoxin. Formation of lipid A disaccharides from monosaccharide precursors in extracts of Escherichia coli. J. Biol. Chem. 259 (1984) 4852–4859. [PMID: 6370995]
2.	Crowell, D.N., Reznikoff, W.S. and Raetz, C.R.H. Nucleotide sequence of the Escherichia coli gene for lipid A disaccharide synthase. J. Bacteriol. 169 (1987) 5727–5734. [DOI] [PMID: 2824445]
3.	Metzger, L.E., 4th and Raetz, C.R. Purification and characterization of the lipid A disaccharide synthase (LpxB) from Escherichia coli, a peripheral membrane protein. Biochemistry 48 (2009) 11559–11571. [DOI] [PMID: 19883124]
4.	Bohl, T.E., Shi, K., Lee, J.K. and Aihara, H. Crystal structure of lipid A disaccharide synthase LpxB from Escherichia coli. Nat. Commun. 9:377 (2018). [DOI] [PMID: 29371662]

[EC 2.4.1.182 created 1990, modified 2021]

2.7.1.166

Relevance: 33.7%

Accepted name:

3-deoxy-D-manno-octulosonic acid kinase

Reaction:

α-Kdo-(2→6)-lipid IV_A + ATP = 4-O-phospho-α-Kdo-(2→6)-lipid IV_A + ADP

Glossary:

(Kdo)-lipid IV_A = α-Kdo-(2→6)-lipid IV_A = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
(4-O-phospho-KDO)-lipid IV_A = 4-O-phospho-α-Kdo-(2→6)-lipid IV_A = (3-deoxy-4-O-phosphono-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose

Other name(s):

kdkA (gene name); Kdo kinase

Systematic name:

ATP:(Kdo)-lipid IV_A 3-deoxy-α-D-manno-oct-2-ulopyranose 4-phosphotransferase

Comments:

The enzyme phosphorylates the 4-OH position of Kdo in (Kdo)-lipid IV_A.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Brabetz, W., Muller-Loennies, S. and Brade, H. 3-Deoxy-D-manno-oct-2-ulosonic acid (Kdo) transferase (WaaA) and kdo kinase (KdkA) of Haemophilus influenzae are both required to complement a waaA knockout mutation of Escherichia coli. J. Biol. Chem. 275 (2000) 34954–34962. [DOI] [PMID: 10952982]
2.	Harper, M., Boyce, J.D., Cox, A.D., St Michael, F., Wilkie, I.W., Blackall, P.J. and Adler, B. Pasteurella multocida expresses two lipopolysaccharide glycoforms simultaneously, but only a single form is required for virulence: identification of two acceptor-specific heptosyl I transferases. Infect. Immun. 75 (2007) 3885–3893. [DOI] [PMID: 17517879]
3.	White, K.A., Kaltashov, I.A., Cotter, R.J. and Raetz, C.R. A mono-functional 3-deoxy-D-manno-octulosonic acid (Kdo) transferase and a Kdo kinase in extracts of Haemophilus influenzae. J. Biol. Chem. 272 (1997) 16555–16563. [DOI] [PMID: 9195966]
4.	White, K.A., Lin, S., Cotter, R.J. and Raetz, C.R. A Haemophilus influenzae gene that encodes a membrane bound 3-deoxy-D-manno-octulosonic acid (Kdo) kinase. Possible involvement of kdo phosphorylation in bacterial virulence. J. Biol. Chem. 274 (1999) 31391–31400. [DOI] [PMID: 10531340]

[EC 2.7.1.166 created 2010, modified 2011]

2.4.99.26

Relevance: 33.6%

Accepted name:

O-antigen ligase

Reaction:

a lipid-linked O antigen + a lipid A-core oligosaccharide = a lipopolysaccharide + a polyisoprenyl diphosphate

Other name(s):

waaL (gene name); surface polymer:lipid A-core ligase; rfaL (gene name)

Systematic name:

lipid-linked O-antigen:lipid A-core oligosaccharide O-antigen transferase (configuration-inverting)

Comments:

This Gram-negative bacterial enzyme attaches the polymerized O antigen molecule to the outer core region of the lipid A-core oligosaccharide, finalizing the biosynthesis of the lipopolysaccharide. Prior to the reaction the two substrates are attached to the periplasmic-facing side of the inner membrane, and the enzyme transfers the O-antigen from its polyprenyl diphosphate membrane anchor (usually ditrans,octacis-undecaprenyl diphosphate) to a terminal sugar of the lipid A-core oligosaccharide. Despite the popular name "ligase", the enzyme is not a real ligase, as the reaction does not involve the hydrolysis of a phosphate bond in a triphosphate. The enzyme is embedded in the inner membrane and often has 12 trans-membrane segments. It is a metal-independent inverting glycosyltransferase, and in some cases it can attach surface polymers other than O-antigens to the lipid A-core oligosaccharide.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	MacLachlan, P.R., Kadam, S.K. and Sanderson, K.E. Cloning, characterization, and DNA sequence of the rfaLK region for lipopolysaccharide synthesis in Salmonella typhimurium LT2. J. Bacteriol. 173 (1991) 7151–7163. [DOI] [PMID: 1657881]
2.	Whitfield, C., Amor, P.A. and Koplin, R. Modulation of the surface architecture of gram-negative bacteria by the action of surface polymer:lipid A-core ligase and by determinants of polymer chain length. Mol. Microbiol. 23 (1997) 629–638. [DOI] [PMID: 9157235]
3.	Ruan, X., Loyola, D.E., Marolda, C.L., Perez-Donoso, J.M. and Valvano, M.A. The WaaL O-antigen lipopolysaccharide ligase has features in common with metal ion-independent inverting glycosyltransferases. Glycobiology 22 (2012) 288–299. [DOI] [PMID: 21983211]
4.	Ruan, X., Monjaras Feria, J., Hamad, M. and Valvano, M.A. Escherichia coli and Pseudomonas aeruginosa lipopolysaccharide O-antigen ligases share similar membrane topology and biochemical properties. Mol. Microbiol. 110 (2018) 95–113. [DOI] [PMID: 30047569]

[EC 2.4.99.26 created 2023]

2.4.99.15

Relevance: 33.3%

Accepted name:

(Kdo)₃-lipid IV_A (2-4) 3-deoxy-D-manno-octulosonic acid transferase

Reaction:

α-Kdo-(2→8)-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IV_A + CMP-β-Kdo = α-Kdo-(2→8)-[α-Kdo-(2→4)]-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IV_A + CMP

For diagram of Kdo₄-Lipid IV_A biosynthesis, click here

Glossary:

(Kdo)₃-lipid IV_A = α-Kdo-(2→8)-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IV_A = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→8)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
(Kdo)₄-lipid IV_A = α-Kdo-(2→8)-[α-Kdo-(2→4)]-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IV_A = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→8)-[(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)]-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
CMP-β-Kdo = CMP-3-deoxy-β-D-manno-oct-2-ulopyranosylonate

Other name(s):

Kdo transferase; waaA (gene name); kdtA (gene name); 3-deoxy-D-manno-oct-2-ulosonic acid transferase; 3-deoxy-manno-octulosonic acid transferase; (KDO)₃-lipid IV_A (2-4) 3-deoxy-D-manno-octulosonic acid transferase

Systematic name:

CMP-3-deoxy-D-manno-oct-2-ulosonate:(Kdo)₃-lipid IV_A 3-deoxy-D-manno-oct-2-ulosonate transferase [(2→4) glycosidic bond-forming]

Comments:

The enzyme from Chlamydia psittaci transfers four Kdo residues to lipid A, forming a branched tetrasaccharide with the structure α-Kdo-(2,8)-[α-Kdo-(2,4)]-α-Kdo-(2,4)-α-Kdo (cf. EC 2.4.99.12 [lipid IV_A 3-deoxy-D-manno-octulosonic acid transferase], EC 2.4.99.13 [(Kdo)-lipid IV_A 3-deoxy-D-manno-octulosonic acid transferase], and EC 2.4.99.14 [(Kdo)₂-lipid IV_A (2-8) 3-deoxy-D-manno-octulosonic acid transferase]).

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Brabetz, W., Lindner, B. and Brade, H. Comparative analyses of secondary gene products of 3-deoxy-D-manno-oct-2-ulosonic acid transferases from Chlamydiaceae in Escherichia coli K-12. Eur. J. Biochem. 267 (2000) 5458–5465. [DOI] [PMID: 10951204]
2.	Holst, O., Bock, K., Brade, L. and Brade, H. The structures of oligosaccharide bisphosphates isolated from the lipopolysaccharide of a recombinant Escherichia coli strain expressing the gene gseA [3-deoxy-D-manno-octulopyranosonic acid (Kdo) transferase] of Chlamydia psittaci 6BC. Eur. J. Biochem. 229 (1995) 194–200. [DOI] [PMID: 7744029]

[EC 2.4.99.15 created 2010, modified 2011]

2.4.99.23

Relevance: 33%

Accepted name:

lipopolysaccharide heptosyltransferase I

Reaction:

ADP-L-glycero-β-D-manno-heptose + an α-Kdo-(2→4)-α-Kdo-(2→6)-[lipid A] = ADP + an α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A]

Glossary:

Lipid A is a lipid component of the lipopolysaccharides (LPS) of Gram-negative bacteria. It consists of two glucosamine units connected by a β(1→6) bond and decorated with four to seven acyl chains and up to two phosphate groups.
Hep = L-glycero-D-manno-heptose

Other name(s):

HepI; rfaC (gene name); WaaC; heptosyltransferase I (ambiguous)

Systematic name:

ADP-L-glycero-β-D-manno-heptose:an α-Kdo-(2→4)-α-Kdo-(2→6)-[lipid A] 5-α-heptosyltransferase

Comments:

The enzyme catalyses a glycosylation step in the biosynthesis of the inner core oligosaccharide of the lipopolysaccharide (endotoxin) of many Gram-negative bacteria.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Kadrmas, J.L. and Raetz, C.R. Enzymatic synthesis of lipopolysaccharide in Escherichia coli. Purification and properties of heptosyltransferase i. J. Biol. Chem. 273 (1998) 2799–2807. [DOI] [PMID: 9446588]
2.	de Kievit, T.R. and Lam, J.S. Isolation and characterization of two genes, waaC (rfaC) and waaF (rfaF), involved in Pseudomonas aeruginosa serotype O5 inner-core biosynthesis. J. Bacteriol. 179 (1997) 3451–3457. [DOI] [PMID: 9171387]
3.	Klena, J.D., Gray, S.A. and Konkel, M.E. Cloning, sequencing, and characterization of the lipopolysaccharide biosynthetic enzyme heptosyltransferase I gene (waaC) from Campylobacter jejuni and Campylobacter coli. Gene 222 (1998) 177–185. [DOI] [PMID: 9831648]
4.	Gronow, S., Oertelt, C., Ervela, E., Zamyatina, A., Kosma, P., Skurnik, M. and Holst, O. Characterization of the physiological substrate for lipopolysaccharide heptosyltransferases I and II. J Endotoxin Res 7 (2001) 263–270. [PMID: 11717579]
5.	Grizot, S., Salem, M., Vongsouthi, V., Durand, L., Moreau, F., Dohi, H., Vincent, S., Escaich, S. and Ducruix, A. Structure of the Escherichia coli heptosyltransferase WaaC: binary complexes with ADP and ADP-2-deoxy-2-fluoro heptose. J. Mol. Biol. 363 (2006) 383–394. [DOI] [PMID: 16963083]

[EC 2.4.99.23 created 2022]

2.4.99.24

Relevance: 32.4%

Accepted name:

lipopolysaccharide heptosyltransferase II

Reaction:

ADP-L-glycero-β-D-manno-heptose + an α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A] = ADP + an α-Hep-(1→3)-α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A]

Glossary:

Other name(s):

HepII; rfaF (gene name); WaaF; heptosyltransferase II

Systematic name:

ADP-L-glycero-β-D-manno-heptose:an α-L-glycero-D-manno-heptosyl-(1→5)-[α-Kdo-(2→4)]-α -Kdo-(2→6)-[lipid A] 3-α-heptosyltransferase

Comments:

The enzyme catalyses a glycosylation step in the biosynthesis of the inner core oligosaccharide of the lipopolysaccharide (endotoxin) of some Gram-negative bacteria.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Allen, A.G., Isobe, T. and Maskell, D.J. Identification and cloning of waaF (rfaF) from Bordetella pertussis and use to generate mutants of Bordetella spp. with deep rough lipopolysaccharide. J. Bacteriol. 180 (1998) 35–40. [DOI] [PMID: 9422589]
2.	Bauer, B.A., Lumbley, S.R. and Hansen, E.J. Characterization of a WaaF (RfaF) homolog expressed by Haemophilus ducreyi. Infect. Immun. 67 (1999) 899–907. [DOI] [PMID: 9916106]
3.	Gronow, S., Brabetz, W. and Brade, H. Comparative functional characterization in vitro of heptosyltransferase I (WaaC) and II (WaaF) from Escherichia coli. Eur. J. Biochem. 267 (2000) 6602–6611. [DOI] [PMID: 11054112]
4.	Gronow, S., Oertelt, C., Ervela, E., Zamyatina, A., Kosma, P., Skurnik, M. and Holst, O. Characterization of the physiological substrate for lipopolysaccharide heptosyltransferases I and II. J Endotoxin Res 7 (2001) 263–270. [PMID: 11717579]
5.	Oldfield, N.J., Moran, A.P., Millar, L.A., Prendergast, M.M. and Ketley, J.M. Characterization of the Campylobacter jejuni heptosyltransferase II gene, waaF, provides genetic evidence that extracellular polysaccharide is lipid A core independent. J. Bacteriol. 184 (2002) 2100–2107. [DOI] [PMID: 11914340]

[EC 2.4.99.24 created 2022]

2.4.99.14

Relevance: 31.8%

Accepted name:

(Kdo)₂-lipid IV_A (2-8) 3-deoxy-D-manno-octulosonic acid transferase

Reaction:

α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IV_A + CMP-β-Kdo = α-Kdo-(2→8)-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IV_A + CMP

For diagram of Kdo₄-Lipid IV_A biosynthesis, click here

Glossary:

(Kdo)₂-lipid IV_A = α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IV_A = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
(Kdo)₃-lipid IV_A = α-Kdo-(2→8)-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IV_A = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→8)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
CMP-β-Kdo = CMP-3-deoxy-β-D-manno-oct-2-ulopyranosylonate

Other name(s):

Kdo transferase; waaA (gene name); kdtA (gene name); 3-deoxy-D-manno-oct-2-ulosonic acid transferase; 3-deoxy-manno-octulosonic acid transferase; (KDO)₂-lipid IV_A (2-8) 3-deoxy-D-manno-octulosonic acid transferase

Systematic name:

CMP-3-deoxy-D-manno-oct-2-ulosonate:(Kdo)₂-lipid IV_A 3-deoxy-D-manno-oct-2-ulosonate transferase [(2→8) glycosidic bond-forming]

Comments:

The enzymes from Chlamydia transfer three or more 3-deoxy-D-manno-oct-2-ulosonate residues and generate genus-specific epitopes.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Lobau, S., Mamat, U., Brabetz, W. and Brade, H. Molecular cloning, sequence analysis, and functional characterization of the lipopolysaccharide biosynthetic gene kdtA encoding 3-deoxy-α-D-manno-octulosonic acid transferase of Chlamydia pneumoniae strain TW-183. Mol. Microbiol. 18 (1995) 391–399. [DOI] [PMID: 8748024]
2.	Mamat, U., Baumann, M., Schmidt, G. and Brade, H. The genus-specific lipopolysaccharide epitope of Chlamydia is assembled in C. psittaci and C. trachomatis by glycosyltransferases of low homology. Mol. Microbiol. 10 (1993) 935–941. [DOI] [PMID: 7523826]
3.	Belunis, C.J., Mdluli, K.E., Raetz, C.R. and Nano, F.E. A novel 3-deoxy-D-manno-octulosonic acid transferase from Chlamydia trachomatis required for expression of the genus-specific epitope. J. Biol. Chem. 267 (1992) 18702–18707. [PMID: 1382060]

[EC 2.4.99.14 created 2010, modified 2011]

2.4.99.25

Relevance: 31.7%

Accepted name:

lipopolysaccharide heptosyltransferase III

Reaction:

ADP-L-glycero-β-D-manno-heptose + an α-Hep-(1→3)-4-O-phospho-α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A] = ADP + an α-Hep-(1→7)-α-Hep-(1→3)-4-O-phospho-α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A]

Glossary:

Other name(s):

waaQ (gene name); rfaQ (gene name)

Systematic name:

ADP-L-glycero-β-D-manno-heptose:an α-Hep-(1→3)-4-O-phospho-α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A] heptose^I 7-α-heptosyltransferase

Comments:

The enzyme catalyses a glycosylation step in the biosynthesis of the inner core oligosaccharide of the lipopolysaccharide (endotoxin) of some Gram-negative bacteria.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Mudapaka, J. and Taylor, E.A. Cloning and characterization of the Escherichia coli heptosyltransferase III: Exploring substrate specificity in lipopolysaccharide core biosynthesis. FEBS Lett. 589 (2015) 1423–1429. [DOI] [PMID: 25957775]

[EC 2.4.99.25 created 2022]

1.14.15.14

Relevance: 30.9%

Accepted name:

methyl-branched lipid ω-hydroxylase

Reaction:

a methyl-branched lipid + O₂ + 2 reduced ferredoxin [iron-sulfur] cluster + 2 H⁺ = an ω-hydroxy-methyl-branched lipid + H₂O + 2 oxidized ferredoxin [iron-sulfur] cluster

Other name(s):

CYP124

Systematic name:

methyl-branched lipid,reduced-ferredoxin:oxygen oxidoreductase (ω-hydroxylating)

Comments:

The enzyme, found in pathogenic and nonpathogenic mycobacteria species, actinomycetes, and some proteobacteria, hydroxylates the ω-carbon of a number of methyl-branched lipids, including (2E,6E)-farnesol, phytanate, geranylgeraniol, 15-methylpalmitate and (2E,6E)-farnesyl diphosphate. It is a P-450 heme-thiolate enzyme.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB

References:

1.	Johnston, J.B., Kells, P.M., Podust, L.M. and Ortiz de Montellano, P.R. Biochemical and structural characterization of CYP124: a methyl-branched lipid ω-hydroxylase from Mycobacterium tuberculosis. Proc. Natl. Acad. Sci. USA 106 (2009) 20687–20692. [DOI] [PMID: 19933331]

[EC 1.14.15.14 created 2015]

1.14.19.34

Relevance: 28.6%

Accepted name:

acyl-lipid (9+3)-(E)-desaturase

Reaction:

(1) an oleoyl-[glycerolipid] + 2 ferrocytochrome b₅ + O₂ + 2 H⁺ = a (9Z,12E)-octadeca-9,12-dienoyl-[glycerolipid] + 2 ferricytochrome b₅ + 2 H₂O
(2) a palmitoleoyl-[glycerolipid] + 2 ferrocytochrome b₅ + O₂ + 2 H⁺ = a (9Z,12E)-hexadeca-9,12-dienoyl-[glycerolipid] + 2 ferricytochrome b₅ + 2 H₂O

Other name(s):

acyl-lipid 12-(E)-desaturase; DsFAD2-1; FADX

Systematic name:

Δ⁹ acyl-lipid,ferrocytochrome b₅:oxygen oxidoreductase (12,13 trans-dehydrogenating)

Comments:

The enzymes from the plants Dimorphotheca sinuata (African daisy) and Vernicia fordii (tung oil tree) insert a trans double bond in position C-12 of oleate and palmitoleate incorporated into glycerolipids. The enzyme introduces the new double bond at a position three carbons away from an existing double bond at position 9, towards the methyl end of the fatty acid. The enzyme from tung oil tree also possesses the activity of EC 1.14.19.33, Δ¹² acyl-lipid conjugase.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Dyer, J.M., Chapital, D.C., Kuan, J.C., Mullen, R.T., Turner, C., McKeon, T.A. and Pepperman, A.B. Molecular analysis of a bifunctional fatty acid conjugase/desaturase from tung. Implications for the evolution of plant fatty acid diversity. Plant Physiol. 130 (2002) 2027–2038. [DOI] [PMID: 12481086]
2.	Cahoon, E.B. and Kinney, A.J. Dimorphecolic acid is synthesized by the coordinate activities of two divergent Δ¹²-oleic acid desaturases. J. Biol. Chem. 279 (2004) 12495–12502. [DOI] [PMID: 14718523]

[EC 1.14.19.34 created 2015]

3.6.1.54

Relevance: 28.2%

Accepted name:

UDP-2,3-diacylglucosamine diphosphatase

Reaction:

a UDP-2-N,3-O-bis[(3R)-3-hydroxyacyl]-α-D-glucosamine + H₂O = a lipid X + UMP

For diagram of lipid IV_A biosynthesis, click here

Glossary:

a lipid X = 2-N-[(3R)-3-hydroxyacyl]-3-O-[(3R)-3-hydroxyacyl]-α-D-glucosamine 1-phosphate =
2-N,3-O-bis[(3R)-3-hydroxyacyl]-α-D-glucosamine

Other name(s):

lpxH (gene name); UDP-2,3-diacylglucosamine hydrolase; UDP-2,3-diacylglucosamine pyrophosphatase; ybbF (gene name); UDP-2,3-bis[(3R)-3-hydroxymyristoyl]-α-D-glucosamine 2,3-bis[(3R)-3-hydroxymyristoyl]-β-D-glucosaminyl 1-phosphate phosphohydrolase (incorrect); UDP-2-N,3-O-bis[(3R)-3-hydroxytetradecanoyl]-α-D-glucosamine 2-N,3-O-bis[(3R)-3-hydroxytetradecanoyl]-α-D-glucosaminyl 1-phosphate phosphohydrolase

Systematic name:

UDP-2-N,3-O-bis[(3R)-3-hydroxyacyl]-α-D-glucosamine 2-N,3-O-bis[(3R)-3-hydroxyacyl]-α-D-glucosamine-1-phosphate phosphohydrolase

Comments:

The enzyme catalyses a step in the biosynthesis of lipid A.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB

References:

1.	Babinski, K.J., Ribeiro, A.A. and Raetz, C.R. The Escherichia coli gene encoding the UDP-2,3-diacylglucosamine pyrophosphatase of lipid A biosynthesis. J. Biol. Chem. 277 (2002) 25937–25946. [DOI] [PMID: 12000770]
2.	Babinski, K.J., Kanjilal, S.J. and Raetz, C.R. Accumulation of the lipid A precursor UDP-2,3-diacylglucosamine in an Escherichia coli mutant lacking the lpxH gene. J. Biol. Chem. 277 (2002) 25947–25956. [DOI] [PMID: 12000771]
3.	Okada, C., Wakabayashi, H., Kobayashi, M., Shinoda, A., Tanaka, I. and Yao, M. Crystal structures of the UDP-diacylglucosamine pyrophosphohydrase LpxH from Pseudomonas aeruginosa. Sci. Rep. 6:32822 (2016). [DOI] [PMID: 27609419]
4.	Cho, J., Lee, C.J., Zhao, J., Young, H.E. and Zhou, P. Structure of the essential Haemophilus influenzae UDP-diacylglucosamine pyrophosphohydrolase LpxH in lipid A biosynthesis. Nat Microbiol 1:16154 (2016). [DOI] [PMID: 27780190]
5.	Arenas, J., Pupo, E., de Jonge, E., Perez-Ortega, J., Schaarschmidt, J., van der Ley, P. and Tommassen, J. Substrate specificity of the pyrophosphohydrolase LpxH determines the asymmetry of Bordetella pertussis lipid A. J. Biol. Chem. 294 (2019) 7982–7989. [DOI] [PMID: 30926608]

[EC 3.6.1.54 created 2010, modified 2021]

1.14.19.16

Relevance: 28%

Accepted name:

linoleoyl-lipid Δ¹² conjugase (11E,13Z-forming)

Reaction:

a linoleoyl-[glycerolipid] + 2 ferrocytochrome b₅ + O₂ + 2 H⁺ = a (9Z,11E,13Z)-octadeca-9,11,13-trienoyl-[glycerolipid] + 2 ferricytochrome b₅ + 2 H₂O

Glossary:

punicate = (9Z,11E,13Z)-octadeca-9,11,13-trienoate
linoleate = (9Z,12Z)-octadeca-9,12-dienoate

Other name(s):

Fac (gene name)

Systematic name:

linoleoyl-lipid,ferrocytochrome-b₅:oxygen 11,14 allylic oxidase (11E,13Z-forming)

Comments:

The enzyme, characterized from the plants Punica granatum (pomegranate) and Trichosanthes kirilowii (Mongolian snake-gourd), converts a single cis double bond at position 12 of linoleate incorporated into phosphatidylcholine into conjugated 11-trans and 13-cis double bonds. cf. EC 1.14.19.33, Δ¹² acyl-lipid conjugase (11E,13E-forming).

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Hornung, E., Pernstich, C. and Feussner, I. Formation of conjugated Δ¹¹Δ¹³-double bonds by Δ¹²-linoleic acid (1,4)-acyl-lipid-desaturase in pomegranate seeds. Eur. J. Biochem. 269 (2002) 4852–4859. [DOI] [PMID: 12354116]
2.	Iwabuchi, M., Kohno-Murase, J. and Imamura, J. Δ¹²-oleate desaturase-related enzymes associated with formation of conjugated trans-Δ^11, cis-Δ¹³ double bonds. J. Biol. Chem. 278 (2003) 4603–4610. [DOI] [PMID: 12464604]

[EC 1.14.19.16 created 2015]

2.4.99.27

Relevance: 27.9%

Accepted name:

O-antigen polymerase Wzy

Reaction:

n lipid-linked O-antigen repeat units = a lipid-linked O antigen + (n−1) polyisoprenyl diphosphate

Other name(s):

wzy (gene name); rfc (gene name); Wzy O-antigen polymerase; Wzy polymerase

Systematic name:

lipid-linked O-antigen repeat unit:O-antigen O-antigen repeat-unit transferase

Comments:

The Wzy-type polymerase polymerizes O antigen repeat unit oligosaccharides that are anchored to the periplasmic face of the inner membrane, forming an O antigen polysaccharide that is still anchored to the membrane. A Wzz chain length regulator (sometimes referred to as an O-antigen co-polymerase) normally interacts with Wzy to confer a distinctive modal chain length distribution. The resultant polysaccharide is transferred from the membrane anchor to the lipid A-core oligosaccharide by EC 2.4.99.26, O-antigen ligase, forming a complete lipopolysaccharide structure. There is an enormous diversity of O antigen polymerases with different specificities, reflecting the variability in the structure and composition of O-antigens.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Collins, L.V. and Hackett, J. Molecular cloning, characterization, and nucleotide sequence of the rfc gene, which encodes an O-antigen polymerase of Salmonella typhimurium. J. Bacteriol. 173 (1991) 2521–2529. [DOI] [PMID: 1707412]
2.	Woodward, R., Yi, W., Li, L., Zhao, G., Eguchi, H., Sridhar, P.R., Guo, H., Song, J.K., Motari, E., Cai, L., Kelleher, P., Liu, X., Han, W., Zhang, W., Ding, Y., Li, M. and Wang, P.G. In vitro bacterial polysaccharide biosynthesis: defining the functions of Wzy and Wzz. Nat. Chem. Biol. 6 (2010) 418–423. [DOI] [PMID: 20418877]
3.	Kenyon, J.J. and Reeves, P.R. The Wzy O-antigen polymerase of Yersinia pseudotuberculosis O:2a has a dependence on the Wzz chain-length determinant for efficient polymerization. FEMS Microbiol. Lett. 349 (2013) 163–170. [DOI] [PMID: 24164168]
4.	Islam, S.T., Huszczynski, S.M., Nugent, T., Gold, A.C. and Lam, J.S. Conserved-residue mutations in Wzy affect O-antigen polymerization and Wzz-mediated chain-length regulation in Pseudomonas aeruginosa PAO1. Sci. Rep. 3:3441 (2013). [DOI] [PMID: 24309320]
5.	Islam, S.T. and Lam, J.S. Synthesis of bacterial polysaccharides via the Wzx/Wzy-dependent pathway. Can. J. Microbiol. 60 (2014) 697–716. [DOI] [PMID: 25358682]
6.	Nath, P. and Morona, R. Mutational analysis of the major periplasmic loops of Shigella flexneri Wzy: identification of the residues affecting O antigen modal chain length control, and Wzz-dependent polymerization activity. Microbiology (Reading) 161 (2015) 774–785. [DOI] [PMID: 25627441]
7.	Merino, S., Gonzalez, V. and Tomas, J.M. The first sugar of the repeat units is essential for the Wzy polymerase activity and elongation of the O-antigen lipopolysaccharide. Future Microbiol 11 (2016) 903–918. [DOI] [PMID: 27357519]

[EC 2.4.99.27 created 2023]

2.4.1.130

Transferred entry:

dolichyl-phosphate-mannose—glycolipid α-mannosyltransferase. Now covered by EC 2.4.1.258 (Dol-P-Man:Man₅GlcNAc₂-PP-Dol α-1,3-mannosyltransferase), EC 2.4.1.259 (Dol-P-Man:Man₆GlcNAc₂-PP-Dol α-1,2-mannosyltransferase), EC 2.4.1.260 (Dol-P-Man:Man₇GlcNAc₂-PP-Dol α-1,6-mannosyltransferase) and EC 2.4.1.261 (Dol-P-Man:Man₈GlcNAc₂-PP-Dol α-1,2-mannosyltransferase).

[EC 2.4.1.130 created 1984, deleted 2011]

1.11.1.12

Relevance: 27%

Accepted name:

phospholipid-hydroperoxide glutathione peroxidase

Reaction:

2 glutathione + a hydroperoxy-fatty-acyl-[lipid] = glutathione disulfide + a hydroxy-fatty-acyl-[lipid] + H₂O

Other name(s):

peroxidation-inhibiting protein; PHGPX; peroxidation-inhibiting protein:peroxidase,glutathione (phospholipid hydroperoxide-reducing); phospholipid hydroperoxide glutathione peroxidase; hydroperoxide glutathione peroxidase

Systematic name:

glutathione:lipid-hydroperoxide oxidoreductase

Comments:

A protein containing a selenocysteine residue. The products of action of EC 1.13.11.12 lipoxygenase on phospholipids can act as acceptors; H₂O₂ can also act, but much more slowly (cf. EC 1.11.1.9 glutathione peroxidase).

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 97089-70-8

References:

1.	Ursini, F., Maiorino, M. and Gregolin, C. The selenoenzyme phospholipid hydroperoxide glutathione peroxidase. Biochim. Biophys. Acta 839 (1985) 62–70. [DOI] [PMID: 3978121]
2.	Schnurr, K., Belkner, J., Ursini, F., Schewe, T. and Kuhn, H. The selenoenzyme phospholipid hydroperoxide glutathione peroxidase controls the activity of the 15-lipoxygenase with complex substrates and preserves the specificity of the oxygenation products. J. Biol. Chem. 271 (1996) 4653–4658. [DOI] [PMID: 8617728]

[EC 1.11.1.12 created 1989, modified 2015]

2.3.3.2

Relevance: 26.8%

Accepted name:

decylcitrate synthase

Reaction:

lauroyl-CoA + H₂O + oxaloacetate = (2S,3S)-2-hydroxytridecane-1,2,3-tricarboxylate + CoA

For diagram of reaction, click here

Other name(s):

2-decylcitrate synthase; (2S,3S)-2-hydroxytridecane-1,2,3-tricarboxylate oxaloacetate-lyase (CoA-acylating)

Systematic name:

dodecanoyl-CoA:oxaloacetate C-dodecanoyltransferase (thioester-hydrolysing, 1-carboxyundecyl-forming)

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 9068-72-8

References:

1.	Maahlén, A. and Gatenbeck, S. A metabolic variation in Penicillium spiculisporum Lehman. II. Purification and some properties of the enzyme synthesizing (-)-decylcitric acid. Acta Chem. Scand. 22 (1968) 2617–2623. [PMID: 5719165]
2.	Maahlén, A. Properties of 2-decylcitrate synthase from Penicillium spiculisporum Lehman. Eur. J. Biochem. 22 (1971) 104–114. [DOI] [PMID: 5099208]

[EC 2.3.3.2 created 1972 as EC 4.1.3.23, transferred 2002 to EC 2.3.3.2]

7.5.2.14

Relevance: 25.8%

Accepted name:

ABC-type homopolymeric O-antigen exporter

Reaction:

ATP + a lipid-linked O antigen[cytosol] + H₂O = ADP + phosphate + a lipid-linked O antigen[periplasm]

Other name(s):

wzm (gene name); wzt (gene name)

Systematic name:

ATP phosphohydrolase (ABC-type, homopolymeric O-antigen exporting)

Comments:

Unlike heteropolymeric O antigens, which are polymerized in the periplasm by EC 2.4.99.27, O antigen polymerase Wzy, homopolymeric O antigens are polymerized inside the cytoplasm by a progressive transfer of sugar monomers to a growing chain attached to a polyprenyl diphosphate membrane anchor. When the chain reaches its full length it is transported across the cytoplasmic membrane by this ABC-type transporter, which consists of an ATP-binding subunit (Wzt) and an integral membrane protein (Wzm). Wzm proteins are poorly conserved in their primary sequence. Once in the periplasm, the O antigen is ligated to the lipid A-core complex by EC 2.4.99.26, O-antigen ligase.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Kido, N., Torgov, V.I., Sugiyama, T., Uchiya, K., Sugihara, H., Komatsu, T., Kato, N. and Jann, K. Expression of the O9 polysaccharide of Escherichia coli: sequencing of the E. coli O9 rfb gene cluster, characterization of mannosyl transferases, and evidence for an ATP-binding cassette transport system. J. Bacteriol. 177 (1995) 2178–2187. [DOI] [PMID: 7536735]
2.	Rocchetta, H.L. and Lam, J.S. Identification and functional characterization of an ABC transport system involved in polysaccharide export of A-band lipopolysaccharide in Pseudomonas aeruginosa. J. Bacteriol. 179 (1997) 4713–4724. [DOI] [PMID: 9244257]
3.	Cuthbertson, L., Powers, J. and Whitfield, C. The C-terminal domain of the nucleotide-binding domain protein Wzt determines substrate specificity in the ATP-binding cassette transporter for the lipopolysaccharide O-antigens in Escherichia coli serotypes O8 and O9a. J. Biol. Chem. 280 (2005) 30310–30319. [DOI] [PMID: 15980069]
4.	Cuthbertson, L., Kimber, M.S. and Whitfield, C. Substrate binding by a bacterial ABC transporter involved in polysaccharide export. Proc. Natl. Acad. Sci. USA 104 (2007) 19529–19534. [DOI] [PMID: 18032609]
5.	Mann, E., Mallette, E., Clarke, B.R., Kimber, M.S. and Whitfield, C. The Klebsiella pneumoniae O12 ATP-binding cassette (ABC) transporter recognizes the terminal residue of its O-antigen polysaccharide substrate. J. Biol. Chem. 291 (2016) 9748–9761. [DOI] [PMID: 26934919]
6.	Mann, E., Kelly, S.D., Al-Abdul-Wahid, M.S., Clarke, B.R., Ovchinnikova, O.G., Liu, B. and Whitfield, C. Substrate recognition by a carbohydrate-binding module in the prototypical ABC transporter for lipopolysaccharide O-antigen from Escherichia coli O9a. J. Biol. Chem. 294 (2019) 14978–14990. [DOI] [PMID: 31416837]

[EC 7.5.2.14 created 2023]

1.14.19.47

Relevance: 25.6%

Accepted name:

acyl-lipid (9-3)-desaturase

Reaction:

(1) an α-linolenoyl-[glycerolipid] + 2 ferrocytochrome b₅ + O₂ + 2 H⁺ = a stearidonoyl-[glycerolipid] + 2 ferricytochrome b₅ + 2 H₂O
(2) a linoleoyl-[glycerolipid] + 2 ferrocytochrome b₅ + O₂ + 2 H⁺ = a γ-linolenoyl-[glycerolipid] + 2 ferricytochrome b₅ + 2 H₂O

Glossary:

stearidonic acid = (6Z,9Z,12Z,15Z)-octadeca-6,9,12,15-tetraenoic acid

Other name(s):

DES6 (gene name); acyl-lipid 6-desaturase; acyl-lipid Δ⁶-desaturase; Δ⁶-desaturase (ambiguous)

Systematic name:

Δ⁹ acyl-[glycerolipid],ferrocytochrome b₅:oxygen oxidoreductase (6,7-cis-dehydrogenating)

Comments:

The enzyme, characterized from the moss Physcomitrella patens and the plant Borago officinalis (borage), introduces a cis double bond at carbon 6 of several acyl-lipids that contain an existing Δ⁹ cis double bond. The enzyme contains a cytochrome b₅ domain that acts as the electron donor for the active site of the desaturase.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Sayanova, O., Smith, M.A., Lapinskas, P., Stobart, A.K., Dobson, G., Christie, W.W., Shewry, P.R. and Napier, J.A. Expression of a borage desaturase cDNA containing an N-terminal cytochrome b₅ domain results in the accumulation of high levels of Δ⁶-desaturated fatty acids in transgenic tobacco. Proc. Natl. Acad. Sci. USA 94 (1997) 4211–4216. [DOI] [PMID: 9108131]
2.	Girke, T., Schmidt, H., Zähringer, U., Reski, R. and Heinz, E. Identification of a novel Δ⁶-acyl-group desaturase by targeted gene disruption in Physcomitrella patens. Plant J. 15 (1998) 39–48. [DOI] [PMID: 9744093]

[EC 1.14.19.47 created 2015]

2.4.1.180

Relevance: 25.2%

Accepted name:

lipopolysaccharide N-acetylmannosaminouronosyltransferase

Reaction:

UDP-N-acetyl-α-D-mannosaminouronate + N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol = UDP + N-acetyl-β-D-mannosaminouronyl-(1→4)-N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol

Glossary:

N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol = lipid I = GlcNAc-pyrophosphorylundecaprenol = ditrans,octacis-undecaprenyl-N-acetyl-α-D-glucosaminyl diphosphate

Other name(s):

ManNAcA transferase; uridine diphosphoacetylmannosaminuronate-acetylglucosaminylpyrophosphorylundecaprenol acetylmannosaminuronosyltransferase; UDP-N-acetyl-β-D-mannosaminouronate:lipid I N-acetyl-β-D-mannosaminouronosyltransferase (incorrect)

Systematic name:

UDP-N-acetyl-α-D-mannosaminouronate:lipid I N-acetyl-α-D-mannosaminouronosyltransferase

Comments:

Involved in the biosynthesis of common antigen in Enterobacteriaceae.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 113478-30-1

References:

Barr, K., Ward, S., Meier-Dieter, U., Mayer, H. and Rick, P.D. Characterization of an Escherichia coli rff mutant defective in transfer of N-acetylmannosaminuronic acid (ManNAcA) from UDP-ManNAcA to a lipid-linked intermediate involved in enterobacterial common antigen synthesis. J. Bacteriol. 170 (1988) 228–233. [DOI] [PMID: 3275612]

[EC 2.4.1.180 created 1990, modified 2011]

2.4.1.325

Relevance: 25%

Accepted name:

TDP-N-acetylfucosamine:lipid II N-acetylfucosaminyltransferase

Reaction:

dTDP-4-acetamido-4,6-dideoxy-α-D-galactose + N-acetyl-β-D-mannosaminouronyl-(1→4)-N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol = dTDP + 4-acetamido-4,6-dideoxy-α-D-galactosyl-(1→4)-N-acetyl-β-D-mannosaminouronyl-(1→4)-N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol

Glossary:

dTDP-4-acetamido-4,6-dideoxy-α-D-galactose = dTDP-N-acetyl-α-D-fucosamine
a lipid II = an undecaprenyldiphospho-N-acetyl-(N-acetylglucosaminyl)muramoyl peptide; the peptide element refers to L-alanyl-D-γ-glutamyl-L-lysyl/meso-2,6-diaminopimelyl-D-alanyl-D-alanine or a modified version thereof = an undecaprenyldiphospho-4-O-(N-acetyl-β-D-glucosaminyl)-3-O-peptidyl-α-N-acetylmuramate; the peptide element refers to L-alanyl-D-γ-glutamyl-L-lysyl/meso-2,6-diaminopimelyl-D-alanyl-D-alanine or a modified version thereof
lipid III = N-acetyl-β-D-fucosyl-(1→4)-N-acetyl-β-D-mannosaminouronyl-(1→4)-N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol

Other name(s):

TDP-Fuc4NAc:lipid II Fuc4NAc-transferase; TDP-Fuc4NAc:lipid II Fuc4NAc transferase; wecF (gene name)

Systematic name:

dTDP-N-acetyl-α-D-fucose:N-acetyl-β-D-mannosaminouronyl-(1→4)-N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol N-acetylfucosaminyltransferase

Comments:

Involved in the enterobacterial common antigen (ECA) biosynthesis in the bacterium Escherichia coli. The trisaccharide of the product (lipid III) is the repeat unit of ECA.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Rahman, A., Barr, K. and Rick, P.D. Identification of the structural gene for the TDP-Fuc4NAc:lipid II Fuc4NAc transferase involved in synthesis of enterobacterial common antigen in Escherichia coli K-12. J. Bacteriol. 183 (2001) 6509–6516. [DOI] [PMID: 11673418]

[EC 2.4.1.325 created 2014]

1.14.99.31

Transferred entry:

myristoyl-CoA 11-(E) desaturase. Now classified as EC 1.14.19.24, myristoyl-CoA 11-(E) desaturase

[EC 1.14.99.31 created 2000, deleted 2015]

1.14.19.39

Relevance: 24.8%

Accepted name:

acyl-lipid Δ¹²-acetylenase

Reaction:

linoleoyl-[glycerolipid] + 2 ferrocytochrome b₅ + O₂ + 2 H⁺ = crepenynyl-[glycerolipid] + 2 ferricytochrome b₅ + 2 H₂O

Glossary:

crepenynate = (9Z)-octadec-9-en-12-ynoate

Systematic name:

Δ¹² acyl-lipid,ferrocytochrome-b₅:oxygen oxidoreductase (12,13-dehydrogenating)

Comments:

The enzyme, characterized from the plant Crepis alpina, converts the double bond at position 12 of linoleate into a triple bond. The product is the main fatty acid found in triacylglycerols in the seed oil of Crepis alpina.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Banas, A., Bafor, M., Wiberg, E., Lenman, M., Staahl, U. and Stymne, S. Biosynthesis of an acetylenic fatty acid in microsomal preparations from developing seeds Crepis alpina. Physiol. Biochem. Mol. Biol. Plant. [Proc. Int. Symp. Plant Lipids] 12th (1997) 57–59.
2.	Lee, M., Lenman, M., Banas, A., Bafor, M., Singh, S., Schweizer, M., Nilsson, R., Liljenberg, C., Dahlqvist, A., Gummeson, P.O., Sjodahl, S., Green, A. and Stymne, S. Identification of non-heme di-iron proteins that catalyze triple bond and epoxy group formation. Science 280 (1998) 915–918. [DOI] [PMID: 9572738]
3.	Nam, J.W. and Kappock, T.J. Cloning and transcriptional analysis of Crepis alpina fatty acid desaturases affecting the biosynthesis of crepenynic acid. J. Exp. Bot. 58 (2007) 1421–1432. [DOI] [PMID: 17329262]

[EC 1.14.19.39 created 2000 as EC 1.14.99.33, transferred 2015 to EC 1.14.19.39]

1.14.19.14

Relevance: 24.7%

Accepted name:

linoleoyl-lipid Δ⁹ conjugase

Reaction:

a linoleoyl-[glycerolipid] + reduced acceptor + O₂ = an (8E,10E,12Z)-octadeca-8,10,12-trienoyl-[glycerolipid] + acceptor + 2 H₂O

Glossary:

calendate = (8E,10E,12Z)-octadeca-8,10,12-trienoate

Systematic name:

linoleoyl-lipid,reduced acceptor:oxygen 8,11-allylic oxidase (8E,10E-forming)

Comments:

The enzyme, characterized from the plant Calendula officinalis, converts a single cis double bond at position 9 of fatty acids incorporated into glycerolipids into two conjugated trans double bonds at positions 8 and 10.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Qiu, X., Reed, D.W., Hong, H., MacKenzie, S.L. and Covello, P.S. Identification and analysis of a gene from Calendula officinalis encoding a fatty acid conjugase. Plant Physiol. 125 (2001) 847–855. [PMID: 11161042]
2.	Cahoon, E.B., Ripp, K.G., Hall, S.E. and Kinney, A.J. Formation of conjugated Δ⁸,Δ¹⁰-double bonds by Δ¹²-oleic-acid desaturase-related enzymes: biosynthetic origin of calendic acid. J. Biol. Chem. 276 (2001) 2637–2643. [DOI] [PMID: 11067856]

[EC 1.14.19.14 created 2015]

1.14.19.22

Relevance: 24.7%

Accepted name:

acyl-lipid ω-6 desaturase (cytochrome b₅)

Reaction:

an oleoyl-[glycerolipid] + 2 ferrocytochrome b₅ + O₂ + 2 H⁺ = a linoleoyl-[glycerolipid] + 2 ferricytochrome b₅ + 2 H₂O

Other name(s):

oleate desaturase (ambiguous); linoleate synthase (ambiguous); oleoyl-CoA desaturase (incorrect); oleoylphosphatidylcholine desaturase (ambiguous); phosphatidylcholine desaturase (ambiguous); n-6 desaturase (ambiguous); FAD2 (gene name)

Systematic name:

1-acyl-2-oleoyl-sn-glycero-3-phosphocholine,ferrocytochrome-b₅:oxygen oxidoreductase (12,13 cis-dehydrogenating)

Comments:

This microsomal enzyme introduces a cis double bond in fatty acids attached to lipid molecules at a location 6 carbons away from the methyl end of the fatty acid. The distance from the carboxylic acid end of the molecule does not affect the location of the new double bond. The most common substrates are oleoyl groups attached to either the sn-1 or sn-2 position of the glycerol backbone in phosphatidylcholine. cf. EC 1.14.19.23, acyl-lipid ω-6 desaturase (ferredoxin).

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 72536-70-0

References:

1.	Pugh, E.L. and Kates, M. Characterization of a membrane-bound phospholipid desaturase system of Candida lipolytica. Biochim. Biophys. Acta 380 (1975) 442–453. [DOI] [PMID: 166662]
2.	Slack, C.R., Roughan, P.G. and Browse, J. Evidence for an oleoyl phosphatidylcholine desaturase in microsomal preparations from cotyledons of safflower (Carthamus tinctorius) seed. Biochem. J. 179 (1979) 649–656. [PMID: 475773]
3.	Stymne, S. and Appelqvist, L.-A. The biosynthesis of linoleate from oleoyl-CoA via oleoyl-phosphatidylcholine in microsomes of developing safflower seeds. Eur. J. Biochem. 90 (1978) 223–229. [DOI] [PMID: 710426]
4.	Smith, M.A., Cross, A.R., Jones, O.T., Griffiths, W.T., Stymne, S. and Stobart, K. Electron-transport components of the 1-acyl-2-oleoyl-sn-glycero-3-phosphocholine Δ¹²-desaturase (Δ¹²-desaturase) in microsomal preparations from developing safflower (Carthamus tinctorius L.) cotyledons. Biochem. J. 272 (1990) 23–29. [PMID: 2264826]
5.	Kearns, E.V., Hugly, S. and Somerville, C.R. The role of cytochrome b₅ in Δ¹² desaturation of oleic acid by microsomes of safflower (Carthamus tinctorius L.). Arch. Biochem. Biophys. 284 (1991) 431–436. [DOI] [PMID: 1989527]
6.	Miquel, M. and Browse, J. Arabidopsis mutants deficient in polyunsaturated fatty acid synthesis. Biochemical and genetic characterization of a plant oleoyl-phosphatidylcholine desaturase. J. Biol. Chem. 267 (1992) 1502–1509. [PMID: 1730697]

[EC 1.14.19.22 created 1984 as EC 1.3.1.35, transferred 2015 to EC 1.14.19.22]

1.14.19.38

Relevance: 24.2%

Accepted name:

acyl-lipid Δ⁶-acetylenase

Reaction:

(1) a γ-linolenoyl-[glycerolipid] + 2 ferrocytochrome b₅ + O₂ + 2 H⁺ = a (9Z,12Z)-octadeca-9,12-dien-6-ynoyl-[glycerolipid] + 2 ferricytochrome b₅ + 2 H₂O
(2) a stearidonoyl-[glycerolipid] + 2 ferrocytochrome b₅ + O₂ + 2 H⁺ = a (9Z,12Z,15Z)-octadeca-9,12,15-trien-6-ynoyl-[glycerolipid] + 2 ferricytochrome b₅ + 2 H₂O

Glossary:

γ-linolenoate = (6Z,9Z,12Z)-octadeca-6,9,12-trienoate
stearidonate = (6Z,9Z,12Z,15Z)-octadeca-6,9,12,15-tetraenoate
dicranin = (9Z,12Z,15Z)-octadeca-9,12,15-trien-6-ynoic acid

Systematic name:

Δ⁶ acyl-lipid,ferrocytochrome-b₅:oxygen oxidoreductase (6,7-dehydrogenating)

Comments:

The enzyme, characterized from the moss Ceratodon purpureus, converts the double bond at position 6 of γ-linolenate and stearidonate into a triple bond. The product of the latter, dicranin, is the main fatty acid found in C. purpureus. The enzyme contains a cytochrome b₅ domain that acts as the direct electron donor to the desaturase active site. The enzyme also has the activity of EC 1.14.19.47, acyl-lipid (9-3)-desaturase.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Sperling, P., Lee, M., Girke, T., Zähringer, U., Stymne, S. and Heinz, E. A bifunctional Δ⁶-fatty acyl acetylenase/desaturase from the moss Ceratodon purpureus. A new member of the cytochrome b₅ superfamily. Eur. J. Biochem. 267 (2000) 3801–3811. [DOI] [PMID: 10848999]

[EC 1.14.19.38 created 2015]

1.14.19.31

Relevance: 24.1%

Accepted name:

acyl-lipid (7-3)-desaturase

Reaction:

(1) a (7Z,10Z,13Z,16Z,19Z)-docosa-7,10,13,16,19-pentaenoyl-[glycerolipid] + 2 ferrocytochrome b₅ + O₂ + 2 H⁺ = a (4Z,7Z,10Z,13Z,16Z,19Z)-docosa-4,7,10,13,16,19-hexaenoyl-[glycerolipid] + 2 ferricytochrome b₅ + 2 H₂O
(2) a (7Z,10Z,13Z,16Z)-docosa-7,10,13,16-tetraenoyl-[glycerolipid] + 2 ferrocytochrome b₅ + O₂ + 2 H⁺ = a (4Z,7Z,10Z,13Z,16Z)-docosa-4,7,10,13,16-pentaenoyl-[glycerolipid] + 2 ferricytochrome b₅ + 2 H₂O

Glossary:

(7Z,10Z,13Z,16Z)-docosa-7,10,13,16-tetraenoate = adrenate

Other name(s):

D4Des (gene name); des1 (gene name); CrΔ⁴FAD (gene name); acyl-lipid 4-desaturase

Systematic name:

Δ⁷ acyl-lipid,ferrocytochrome b₅:oxygen oxidoreductase (4,5 cis-dehydrogenating)

Comments:

The enzymes from several algae introduce a cis double bond at the 4-position in 22-carbon polyunsaturated fatty acids that contain a Δ⁷ double bond. The enzyme from the fresh water alga Chlamydomonas reinhardtii acts on the 16 carbon fatty acid (7Z,10Z,13Z)-hexadeca-7,10,13-trienoate [5]. The enzyme contains an N-terminal cytochrome b₅ domain that acts as the direct electron donor to the active site of the desaturase, and does not require an external cytochrome.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Qiu, X., Hong, H. and MacKenzie, S.L. Identification of a Δ⁴ fatty acid desaturase from Thraustochytrium sp. involved in the biosynthesis of docosahexanoic acid by heterologous expression in Saccharomyces cerevisiae and Brassica juncea. J. Biol. Chem. 276 (2001) 31561–31566. [DOI] [PMID: 11397798]
2.	Tonon, T., Harvey, D., Larson, T.R. and Graham, I.A. Identification of a very long chain polyunsaturated fatty acid Δ⁴-desaturase from the microalga Pavlova lutheri. FEBS Lett. 553 (2003) 440–444. [DOI] [PMID: 14572666]
3.	Meyer, A., Cirpus, P., Ott, C., Schlecker, R., Zähringer, U. and Heinz, E. Biosynthesis of docosahexaenoic acid in Euglena gracilis: biochemical and molecular evidence for the involvement of a Δ⁴-fatty acyl group desaturase. Biochemistry 42 (2003) 9779–9788. [DOI] [PMID: 12911321]
4.	Zhou, X.R., Robert, S.S., Petrie, J.R., Frampton, D.M., Mansour, M.P., Blackburn, S.I., Nichols, P.D., Green, A.G. and Singh, S.P. Isolation and characterization of genes from the marine microalga Pavlova salina encoding three front-end desaturases involved in docosahexaenoic acid biosynthesis. Phytochemistry 68 (2007) 785–796. [DOI] [PMID: 17291553]
5.	Zäuner, S., Jochum, W., Bigorowski, T. and Benning, C. A cytochrome b₅-containing plastid-located fatty acid desaturase from Chlamydomonas reinhardtii. Eukaryot Cell 11 (2012) 856–863. [DOI] [PMID: 22562471]

[EC 1.14.19.31 created 2015]

2.3.1.129

Relevance: 24.1%

Accepted name:

acyl-[acyl-carrier-protein]—UDP-N-acetylglucosamine O-acyltransferase

Reaction:

a (3R)-3-hydroxyacyl-[acyl-carrier protein] + UDP-N-acetyl-α-D-glucosamine = an [acyl-carrier protein] + a UDP-3-O-[(3R)-3-hydroxyacyl]-N-acetyl-α-D-glucosamine

For diagram of lipid IV_A biosynthesis, click here

Other name(s):

lpxA (gene name); UDP-N-acetylglucosamine acyltransferase; uridine diphosphoacetylglucosamine acyltransferase; acyl-[acyl-carrier-protein]-UDP-N-acetylglucosamine O-acyltransferase; (R)-3-hydroxytetradecanoyl-[acyl-carrier-protein]:UDP-N-acetylglucosamine 3-O-(3-hydroxytetradecanoyl)transferase

Systematic name:

(3R)-3-hydroxyacyl-[acyl-carrier protein]:UDP-N-acetyl-α-D-glucosamine 3-O-(3-hydroxyacyl)transferase

Comments:

Involved with EC 2.4.1.182, lipid-A-disaccharide synthase, and EC 2.7.1.130, tetraacyldisaccharide 4′-kinase, in the biosynthesis of the phosphorylated glycolipid, Lipid A, in the outer membrane of Gram-negative bacteria.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 105843-69-4

References:

1.	Anderson, M.S., Bulawa, C.E. and Raetz, C.R.H. The biosynthesis of gram-negative endotoxin. Formation of lipid A precursors from UDP-GlcNAc in extracts of Escherichia coli. J. Biol. Chem. 260 (1985) 15536–15541. [PMID: 3905795]
2.	Anderson, M.S., Bull, H.G., Galloway, S.M., Kelly, T.M., Mohan, S., Radika, K. and Raetz, C.R. UDP-N-acetylglucosamine acyltransferase of Escherichia coli. The first step of endotoxin biosynthesis is thermodynamically unfavorable. J. Biol. Chem. 268 (1993) 19858–19865. [PMID: 8366124]
3.	Raetz, C.R. and Roderick, S.L. A left-handed parallel β helix in the structure of UDP-N-acetylglucosamine acyltransferase. Science 270 (1995) 997–1000. [DOI] [PMID: 7481807]
4.	Williams, A.H. and Raetz, C.R. Structural basis for the acyl chain selectivity and mechanism of UDP-N-acetylglucosamine acyltransferase. Proc. Natl. Acad. Sci. USA 104 (2007) 13543–13550. [DOI] [PMID: 17698807]
5.	Bainbridge, B.W., Karimi-Naser, L., Reife, R., Blethen, F., Ernst, R.K. and Darveau, R.P. Acyl chain specificity of the acyltransferases LpxA and LpxD and substrate availability contribute to lipid A fatty acid heterogeneity in Porphyromonas gingivalis. J. Bacteriol. 190 (2008) 4549–4558. [DOI] [PMID: 18456814]

[EC 2.3.1.129 created 1990, modified 2021]

2.3.2.30

Relevance: 23.5%

Accepted name:

L-ornithine N^α-acyltransferase

Reaction:

L-ornithine + a (3R)-3-hydroxyacyl-[acyl-carrier protein] = a lyso-ornithine lipid + a holo-[acyl-carrier protein]

Glossary:

a lyso-ornithine lipid = an N^α-[(3R)-hydroxy-acyl]-L-ornithine

Other name(s):

olsB (gene name)

Systematic name:

L-ornithine N^α-(3R)-3-hydroxy-acyltransferase

Comments:

The enzyme, found in bacteria, catalyses the first step in the biosynthesis of ornithine lipids.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Gao, J.L., Weissenmayer, B., Taylor, A.M., Thomas-Oates, J., Lopez-Lara, I.M. and Geiger, O. Identification of a gene required for the formation of lyso-ornithine lipid, an intermediate in the biosynthesis of ornithine-containing lipids. Mol. Microbiol. 53 (2004) 1757–1770. [DOI] [PMID: 15341653]
2.	Vences-Guzman, M.A., Guan, Z., Bermudez-Barrientos, J.R., Geiger, O. and Sohlenkamp, C. Agrobacteria lacking ornithine lipids induce more rapid tumour formation. Environ. Microbiol. 15 (2013) 895–906. [DOI] [PMID: 22958119]

[EC 2.3.2.30 created 2017]