The Enzyme Database

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EC 2.4.1.82     Relevance: 100%
Accepted name: galactinol—sucrose galactosyltransferase
Reaction: α-D-galactosyl-(1→3)-1D-myo-inositol + sucrose = myo-inositol + raffinose
For diagram of stachyose biosynthesis, click here
Glossary: raffinose = β-D-fructofuranosyl α-D-galactopyranosyl-(1→6)-α-D-glucopyranoside
Other name(s): 1-α-D-galactosyl-myo-inositol:sucrose 6-α-D-galactosyltransferase; α-D-galactosyl-(1→3)-myo-inositol:sucrose 6-α-D-galactosyltransferase; raffinose synthase; RafS
Systematic name: α-D-galactosyl-(1→3)-1D-myo-inositol:sucrose 6-α-D-galactosyltransferase
Comments: 4-Nitrophenyl α-D-galactopyranoside can also act as donor. The enzyme also catalyses an exchange reaction between raffinose and sucrose (cf. EC 2.4.1.123, inositol 3-α-galactosyltransferase).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 62213-45-0
References:
1.  Lehle, L. and Tanner, W. The function of myo-inositol in the biosynthesis of raffinose. Purification and characterization of galactinol:sucrose 6-galactosyltransferase from Vicia faba seeds. Eur. J. Biochem. 38 (1973) 103–110. [DOI] [PMID: 4774118]
2.  Lehle, L., Tanner, W. and Kandler, O. Myo-inositol, a cofactor in the biosynthesis of raffinose. Hoppe-Seyler's Z. Physiol. Chem. 351 (1970) 1494–1498. [PMID: 5491608]
[EC 2.4.1.82 created 1976, modified 2003]
 
 
EC 2.4.1.67     Relevance: 93%
Accepted name: galactinol—raffinose galactosyltransferase
Reaction: α-D-galactosyl-(1→3)-1D-myo-inositol + raffinose = myo-inositol + stachyose
For diagram of stachyose biosynthesis, click here
Glossary: raffinose = β-D-fructofuranosyl α-D-galactopyranosyl-(1→6)-α-D-glucopyranoside
Other name(s): galactinol-raffinose galactosyltransferase; stachyose synthetase; α-D-galactosyl-(1→3)-myo-inositol:raffinose galactosyltransferase
Systematic name: α-D-galactosyl-(1→3)-1D-myo-inositol:raffinose galactosyltransferase
Comments: This enzyme also catalyses galactosyl transfer from stachyose to raffinose (shown by labelling) [4]. For synthesis of the substrate, see EC 2.4.1.123, inositol 3-α-galactosyltransferase. See also EC 2.4.1.82, galactinol—sucrose galactosyltransferase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 37277-70-6
References:
1.  Tanner, W. Die Biosynthese der Stachyose. Ber. Dtsch. Bot. Ges. 80 (1967) 111.
2.  Tanner, W. and Kandler, O. Myo-inositol, a cofactor in the biosynthesis of stachyose. Eur. J. Biochem. 4 (1968) 233–239. [DOI] [PMID: 5655499]
3.  Lehle, L. and Tanner, W. The function of myo-inositol in the biosynthesis of raffinose. Purification and characterization of galactinol:sucrose 6-galactosyltransferase from Vicia faba seeds. Eur. J. Biochem. 38 (1973) 103–110. [DOI] [PMID: 4774118]
4.  Kandler, O. and Hopf, H. Occurrence, metabolism and function of oligosaccharides. In: Preiss, J. (Ed.), The Biochemistry of Plant, vol. 3, Academic Press, New York, 1980, pp. 221–270.
[EC 2.4.1.67 created 1972, modified 2003]
 
 
EC 2.4.1.123     Relevance: 92.9%
Accepted name: inositol 3-α-galactosyltransferase
Reaction: UDP-α-D-galactose + myo-inositol = UDP + O-α-D-galactosyl-(1→3)-1D-myo-inositol
For diagram of stachyose biosynthesis, click here
Glossary: O-α-D-galactosyl-(1→3)-1D-myo-inositol = galactinol
Other name(s): UDP-D-galactose:inositol galactosyltransferase; UDP-galactose:myo-inositol 1-α-D-galactosyltransferase; UDPgalactose:myo-inositol 1-α-D-galactosyltransferase; galactinol synthase; inositol 1-α-galactosyltransferase; uridine diphosphogalactose-inositol galactosyltransferase; GolS; UDP-galactose:myo-inositol 3-α-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:myo-inositol 3-α-D-galactosyltransferase
Comments: An enzyme from plants involved in the formation of raffinose and stachyose [cf. EC 2.4.1.67 (galactinol—raffinose galactosyltransferase) and EC 2.4.1.82 (galactinol—sucrose galactosyltransferase)].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 79955-89-8
References:
1.  Pharr, D.M., Sox, H.N., Locy, R.D. and Huber, S.C. Partial characterization of the galactinol forming enzyme from leaves of Cucumis sativus L. Plant Sci. Lett. 23 (1981) 25–33.
[EC 2.4.1.123 created 1984, modified 2003]
 
 
EC 2.4.1.346     Relevance: 65.8%
Accepted name: phosphatidyl-myo-inositol dimannoside synthase
Reaction: (1) GDP-α-D-mannose + 2-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol = GDP + 2,6-di-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol
(2) GDP-α-D-mannose + 2-O-(6-O-acyl-α-D-mannosyl)-1-phosphatidyl-1D-myo-inositol = GDP + 2-O-(6-O-acyl-α-D-mannosyl)-6-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol
Glossary: 1-phosphatidyl-1D-myo-inositol = PtdIns
Other name(s): mannosyltransferase PimB; PimB; guanosine diphosphomannose-phosphatidyl-inositol α-mannosyltransferase (ambiguous)
Systematic name: GDP-α-D-mannose:2-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol 6-α-D-mannosyltransferase (configuration-retaining)
Comments: Requires Mg2+. The enzyme, found in Corynebacteriales, is involved in the biosynthesis of phosphatidyl-myo-inositol mannosides (PIMs).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB
References:
1.  Guerin, M.E., Kaur, D., Somashekar, B.S., Gibbs, S., Gest, P., Chatterjee, D., Brennan, P.J. and Jackson, M. New insights into the early steps of phosphatidylinositol mannoside biosynthesis in mycobacteria: PimB′ is an essential enzyme of Mycobacterium smegmatis. J. Biol. Chem. 284 (2009) 25687–25696. [DOI] [PMID: 19638342]
2.  Mishra, A.K., Batt, S., Krumbach, K., Eggeling, L. and Besra, G.S. Characterization of the Corynebacterium glutamicum Δ pimB′ Δ mgtA double deletion mutant and the role of Mycobacterium tuberculosis orthologues Rv2188c and Rv0557 in glycolipid biosynthesis. J. Bacteriol. 191 (2009) 4465–4472. [DOI] [PMID: 19395496]
3.  Batt, S.M., Jabeen, T., Mishra, A.K., Veerapen, N., Krumbach, K., Eggeling, L., Besra, G.S. and Futterer, K. Acceptor substrate discrimination in phosphatidyl-myo-inositol mannoside synthesis: structural and mutational analysis of mannosyltransferase Corynebacterium glutamicum PimB′. J. Biol. Chem. 285 (2010) 37741–37752. [DOI] [PMID: 20843801]
[EC 2.4.1.346 created 2017]
 
 
EC 2.4.1.345     Relevance: 64.6%
Accepted name: phosphatidyl-myo-inositol α-mannosyltransferase
Reaction: GDP-α-D-mannose + 1-phosphatidyl-1D-myo-inositol = GDP + 2-O-(α-D-mannosyl)-1-phosphatidyl-1D-myo-inositol
Glossary: 1-phosphatidyl-1D-myo-inositol = PtdIns
Other name(s): mannosyltransferase PimA; PimA; guanosine diphosphomannose-phosphatidyl-inositol α-mannosyltransferase (ambiguous)
Systematic name: GDP-α-D-mannose:1-phosphatidyl-1D-myo-inositol 2-α-D-mannosyltransferase (configuration-retaining)
Comments: Requires Mg2+. The enzyme, found in Corynebacteriales, is involved in the biosynthesis of phosphatidyl-myo-inositol mannosides (PIMs).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB
References:
1.  Kordulakova, J., Gilleron, M., Mikusova, K., Puzo, G., Brennan, P.J., Gicquel, B. and Jackson, M. Definition of the first mannosylation step in phosphatidylinositol mannoside synthesis. PimA is essential for growth of mycobacteria. J. Biol. Chem. 277 (2002) 31335–31344. [DOI] [PMID: 12068013]
2.  Gu, X., Chen, M., Wang, Q., Zhang, M., Wang, B. and Wang, H. Expression and purification of a functionally active recombinant GDP-mannosyltransferase (PimA) from Mycobacterium tuberculosis H37Rv. Protein Expr. Purif. 42 (2005) 47–53. [DOI] [PMID: 15939292]
3.  Giganti, D., Albesa-Jove, D., Urresti, S., Rodrigo-Unzueta, A., Martinez, M.A., Comino, N., Barilone, N., Bellinzoni, M., Chenal, A., Guerin, M.E. and Alzari, P.M. Secondary structure reshuffling modulates glycosyltransferase function at the membrane. Nat. Chem. Biol. 11 (2015) 16–18. [DOI] [PMID: 25402770]
4.  Rodrigo-Unzueta, A., Martinez, M.A., Comino, N., Alzari, P.M., Chenal, A. and Guerin, M.E. Molecular basis of membrane association by the phosphatidylinositol mannosyltransferase PimA enzyme from Mycobacteria. J. Biol. Chem. 291 (2016) 13955–13963. [DOI] [PMID: 27189944]
[EC 2.4.1.345 created 2017]
 
 
EC 2.4.3.7     Relevance: 64.4%
Accepted name: α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetylgalactosaminide 6-α-sialyltransferase
Reaction: CMP-N-acetylneuraminate + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-D-galactosaminyl-R = CMP + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-[N-acetyl-α-neuraminyl-(2→6)]-N-acetyl-D-galactosaminyl-R
For diagram of reaction, click here
Other name(s): sialyltransferase; cytidine monophosphoacetylneuraminate-(α-N-acetylneuraminyl-2,3-β-galactosyl-1,3)-N-acetylgalactosaminide-α-2,6-sialyltransferase; α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetyl-galactosaminide α-2,6-sialyltransferase; SIAT7; ST6GALNAC; (α-N-acetylneuraminyl-2,3-β-galactosyl-1,3)-N-acetyl-galactosaminide 6-α-sialyltransferase; CMP-N-acetylneuraminate:(α-N-acetylneuraminyl-2,3-β-D-galactosyl-1,3)-N-acetyl-D-galactosaminide α-2,6-N-acetylneuraminyl-transferase
Systematic name: CMP-N-acetylneuraminate:N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)- N-acetyl-D-galactosaminide galactosamine-6-α-N-acetylneuraminyltransferase
Comments: Attaches N-acetylneuraminic acid in α-2,6-linkage to N-acetylgalactosamine only when present in the structure of α-N-acetylneuraminyl-(2→3)-β-galactosyl-(1→3)-N-acetylgalactosaminyl-R, where R may be protein or p-nitrophenol. Not identical with EC 2.4.3.3 α-N-acetylgalactosaminide α-2,6-sialyltransferase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 129924-24-9
References:
1.  Bergh, M.L.E., Hooghwinkel, G.J.M. and Van den Eijnden, D.H. Biosynthesis of the O-glycosidically linked oligosaccharide chains of fetuin. Indications for an α-N-acetylgalactosaminide α2→6 sialyltransferase with a narrow acceptor specificity in fetal calf liver. J. Biol. Chem. 258 (1983) 7430–7436. [PMID: 6190802]
[EC 2.4.3.7 created 1984 as EC 2.4.99.7, modified 1986, modified 2004, transferred 2022 to EC 2.4.3.7]
 
 
EC 2.4.1.152     Relevance: 63.2%
Accepted name: 4-galactosyl-N-acetylglucosaminide 3-α-L-fucosyltransferase
Reaction: GDP-β-L-fucose + β-D-galactosyl-(1→4)-N-acetyl-D-glucosaminyl-R = GDP + β-D-galactosyl-(1→4)-[α-L-fucosyl-(1→3)]-N-acetyl-D-glucosaminyl-R
For diagram of fucosylneolactotetraosylceramide biosynthesis, click here
Other name(s): Lewis-negative α-3-fucosyltransferase; plasma α-3-fucosyltransferase; guanosine diphosphofucose-glucoside α1→3-fucosyltransferase; galactoside 3-fucosyltransferase; GDP-L-fucose:1,4-β-D-galactosyl-N-acetyl-D-glucosaminyl-R 3-L-fucosyltransferase; GDP-β-L-fucose:1,4-β-D-galactosyl-N-acetyl-D-glucosaminyl-R 3-L-fucosyltransferase; GDP-β-L-fucose:1,4-β-D-galactosyl-N-acetyl-D-glucosaminyl-R 3-α-L-fucosyltransferase; GDP-β-L-fucose:(1→4)-β-D-galactosyl-N-acetyl-D-glucosaminyl-R 3-α-L-fucosyltransferase
Systematic name: GDP-β-L-fucose:β-D-galactosyl-(1→4)-N-acetyl-D-glucosaminyl-R 3-α-L-fucosyltransferase (configuration-inverting)
Comments: Normally acts on a glycoconjugate where R (see reaction) is a glycoprotein or glycolipid. This enzyme fucosylates on O-3 of an N-acetylglucosamine that carries a galactosyl group on O-4, unlike EC 2.4.1.65, 3-galactosyl-N-acetylglucosaminide 4-α-L-fucosyltransferase, which fucosylates on O-4 of an N-acetylglucosamine that carries a galactosyl group on O-3.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 39279-34-0
References:
1.  Johnson, P.H., Yates, A.D. and Watkins, W.M. Human salivary fucosyltransferase: evidence for two distinct α-3-L-fucosyltransferase activities one of which is associated with the Lewis blood Le gene. Biochem. Biophys. Res. Commun. 100 (1981) 1611–1618. [DOI] [PMID: 7295318]
2.  Schachter, H., Narasimhan, S., Gleeson, P. and Vella, G. Glycosyltransferases involved in elongation of N-glycosidically linked oligosaccharides of the complex or N-acetyllactosamine type. Methods Enzymol. 98 (1983) 98–134. [PMID: 6366476]
3.  Ma, B., Wang, G., Palcic, M.M., Hazes, B. and Taylor, D.E. C-terminal amino acids of Helicobacter pylori α1,3/4 fucosyltransferases determine type I and type II transfer. J. Biol. Chem. 278 (2003) 21893–21900. [DOI] [PMID: 12676935]
[EC 2.4.1.152 created 1984, modified 2002, modified 2019]
 
 
EC 2.4.99.7      
Transferred entry: α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetylgalactosaminide 6-α-sialyltransferase. Now EC 2.4.3.7, α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetylgalactosaminide 6-α-sialyltransferase
[EC 2.4.99.7 created 1984, modified 1986, modified 2004, deleted 2022]
 
 
EC 2.4.1.228     Relevance: 61.3%
Accepted name: lactosylceramide 4-α-galactosyltransferase
Reaction: UDP-α-D-galactose + β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of globotetraosylceramide biosynthesis, click here
Glossary: lactosylceramide = β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
Other name(s): Galβ1-4Glcβ1-Cer α1,4-galactosyltransferase; globotriaosylceramide/CD77 synthase; histo-blood group Pk UDP-galactose; UDP-galactose:lactosylceramide 4II-α-D-galactosyltransferase; UDP-galactose:β-D-galactosyl-(1→4)-D-glucosyl(1↔1)ceramide 4II-α-D-galactosyltransferase; UDP-galactose:β-D-galactosyl-(1→4)-D-glucosyl-(1↔1)-ceramide 4II-α-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:β-D-galactosyl-(1→4)-D-glucosyl-(1↔1)-ceramide 4II-α-D-galactosyltransferase
Comments: For explanation of superscript II in systematic name, see 2-carb.37.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 52725-57-2
References:
1.  Bailly, P., Piller, F., Cartron, J.P., Leroy, Y. and Fournet, B. Identification of UDP-galactose: lactose (lactosylceramide) α-4 and β-3 galactosyltransferases in human kidney. Biochem. Biophys. Res. Commun. 141 (1986) 84–91. [DOI] [PMID: 3099784]
2.  Steffensen, R., Carlier, K., Wiels, J., Levery, S.B., Stroud, M., Cedergren, B., Nilsson Sojka, B., Bennett, E.P., Jersild, C. and Clausen, H. Cloning and expression of the histo-blood group Pk UDP-galactose: Galβ1-4Glcβ1-Cer α1,4-galactosyltransferase. Molecular genetic basis of the p phenotype. J. Biol. Chem. 275 (2000) 16723–16729. [DOI] [PMID: 10747952]
3.  Kojima, Y., Fukumoto, S., Furukawa, K., Okajima, T., Wiels, J., Yokoyama, K., Suzuki, Y., Urano, T., Ohta, M. and Furukawa, K. Molecular cloning of globotriaosylceramide/CD77 synthase, a glycosyltransferase that initiates the synthesis of globo series glycosphingolipids. J. Biol. Chem. 275 (2000) 15152–15156. [DOI] [PMID: 10748143]
[EC 2.4.1.228 created 2002]
 
 
EC 2.4.1.87     Relevance: 60.8%
Accepted name: N-acetyllactosaminide 3-α-galactosyltransferase
Reaction: UDP-α-D-galactose + β-D-galactosyl-(1→4)-β-N-acetyl-D-glucosaminyl-R = UDP + α-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-N-acetylglucosaminyl-R (where R can be OH, an oligosaccharide or a glycoconjugate)
Other name(s): α-galactosyltransferase; UDP-Gal:β-D-Gal(1,4)-D-GlcNAc α(1,3)-galactosyltransferase; UDP-Gal:N-acetyllactosaminide α(1,3)-galactosyltransferase; UDP-Gal:N-acetyllactosaminide α-1,3-D-galactosyltransferase; UDP-Gal:Galβ1→4GlcNAc-R α1→3-galactosyltransferase; UDP-galactose-acetyllactosamine α-D-galactosyltransferase; UDPgalactose:β-D-galactosyl-β-1,4-N-acetyl-D-glucosaminyl-glycopeptide α-1,3-D-galactosyltransferase; glucosaminylglycopeptide α-1,3-galactosyltransferase; uridine diphosphogalactose-acetyllactosamine α1→3-galactosyltransferase; uridine diphosphogalactose-acetyllactosamine galactosyltransferase; uridine diphosphogalactose-galactosylacetylglucosaminylgalactosylglucosylceramide galactosyltransferase; β-D-galactosyl-N-acetylglucosaminylglycopeptide α-1,3-galactosyltransferase; UDP-galactose:N-acetyllactosaminide 3-α-D-galactosyltransferase; UDP-galactose:β-D-galactosyl-1,4-β-N-acetyl-D-glucosaminyl-R 3-α-D-galactosyltransferase; UDP-galactose:β-D-galactosyl-(1→4)-β-N-acetyl-D-glucosaminyl-R 3-α-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:β-D-galactosyl-(1→4)-β-N-acetyl-D-glucosaminyl-R 3-α-D-galactosyltransferase
Comments: Acts on β-galactosyl-1,4-N-acetylglucosaminyl termini on asialo-α1-acid glycoprotein and N-acetyllactosamine (β-D-galactosyl-1,4-N-acetyl-β-D-glucosamine), but not on 2′-fucosylated-N-acetyllactosamine. The non-reducing terminal N-acetyllactosamine residues of glycoproteins can also act as acceptor. Now includes EC 2.4.1.124 and EC 2.4.1.151.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 128449-51-4
References:
1.  Basu, M. and Basu, S. Enzymatic synthesis of a blood group B-related pentaglycosylceramide by an α-galactosyltransferase from rabbit bone marrow. J. Biol. Chem. 248 (1973) 1700–1706. [PMID: 4632915]
2.  Blanken, W.M. and van den Eijnden, D.H. Biosynthesis of terminal Gal α 1→3Gal β 1→4GlcNAc-R oligosaccharide sequences on glycoconjugates. Purification and acceptor specificity of a UDP-Gal:N-acetyllactosaminide α 1→3-galactosyltransferase from calf thymus. J. Biol. Chem. 260 (1985) 12927–12934. [PMID: 3932335]
3.  Blake, D.A. and Goldstein, I.J. An α-D-galactosyltransferase activity in Ehrlich ascites tumor cells. Biosynthesis and characterization of a trisaccharide (α-D-galactose-(1→3)-N-acetyllactosamine). J. Biol. Chem. 256 (1981) 5387–5393. [PMID: 6787040]
[EC 2.4.1.87 created 1976, modified 1989, modified 2002 (EC 2.4.1.124 created 1984, incorporated 2002, EC 2.4.1.151 created 1984, incorporated 2002)]
 
 
EC 2.4.1.88     Relevance: 60.4%
Accepted name: globoside α-N-acetylgalactosaminyltransferase
Reaction: UDP-N-acetyl-α-D-galactosamine + N-acetyl-β-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + N-acetyl-α-D-galactosaminyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of globotetraosylceramide biosynthesis, click here
Other name(s): uridine diphosphoacetylgalactosamine-globoside α-acetylgalactosaminyltransferase; Forssman synthase; globoside acetylgalactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetyl-D-galactosaminyl-1,3-D-galactosyl-1,4-D-galactosyl-1,4-D-glucosylceramide α-N-acetyl-D-galactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetyl-D-galactosaminyl-(1→3)-D-galactosyl-(1→4)-D-galactosyl-(1→4)-D-glucosyl-(1↔1)-ceramide α-N-acetyl-D-galactosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-galactosamine:N-acetyl-β-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide α-N-acetyl-D-galactosaminyltransferase
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 52037-97-5
References:
1.  Kijimoto, S., Ishibashi, T. and Makita, A. Biosynthesis of Forssman hapten from globoside by α-N-acetylgalactosaminyltransferase of guinea pig tissues. Biochem. Biophys. Res. Commun. 56 (1974) 177–184. [DOI] [PMID: 4823436]
[EC 2.4.1.88 created 1976]
 
 
EC 2.4.99.2      
Transferred entry: β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminide α-2,3-sialyltransferase. Now EC 2.4.3.2, β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminide α-2,3-sialyltransferase
[EC 2.4.99.2 created 1976, modified 1986, deleted 2022]
 
 
EC 2.4.3.2     Relevance: 60.4%
Accepted name: β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminide α-2,3-sialyltransferase
Reaction: CMP-N-acetyl-β-neuraminate + a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-R = CMP + an N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-R
For diagram of ganglioside biosynthesis, click here
Glossary: a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→4)-[N-acetyl-α-neuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = gangloside GM1a
an N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→4)-[N-acetyl-α-neuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = gangloside GD1a
Other name(s): CMP-N-acetylneuraminate:D-galactosyl-N-acetyl-D-galactosaminyl-(N-acetylneuraminyl)-D-galactosyl-D-glucosyl-(1↔1)-ceramide N-acetylneuraminyltransferase (ambiguous); monosialoganglioside sialyltransferase; CMP-N-acetylneuraminate:a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide N-acetyl-β-neuraminyltransferase
Systematic name: CMP-N-acetyl-β-neuraminate:a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-R α-(2→3)-N-acetylneuraminyltransferase (configuration-inverting)
Comments: The enzyme recognizes the sequence β-D-galactosyl-(1→3)-N-acetyl-D-galactosaminyl (known as type 1 histo-blood group precursor disaccharide) in non-reducing termini of glycan moieties in glycoproteins and glycolipids [1]. When acting on gangloside GM1a, it forms gangloside GD1a [2].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 60202-12-2
References:
1.  Rearick, J.I., Sadler, J.E., Paulson, J.C. and Hill, R.L. Enzymatic characterization of β D-galactoside α2→3 sialyltransferase from porcine submaxillary gland. J. Biol. Chem. 254 (1979) 4444–4451. [PMID: 438198]
2.  Yip, M.C.M. The enzymic synthesis of disialoganglioside: rat brain cytidine-5′-monophospho-N-acetylneuraminic acid: monosialoganglioside (GM1) sialyltransferase. Biochim. Biophys. Acta 306 (1973) 298–306. [DOI] [PMID: 4351506]
[EC 2.4.3.2 created 1976 as EC 2.4.99.2, modified 1986, modified 2017, transferred 2022 to EC 2.4.3.2]
 
 
EC 2.4.1.250     Relevance: 60.1%
Accepted name: D-inositol-3-phosphate glycosyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + 1D-myo-inositol 3-phosphate = 1-O-(2-acetamido-2-deoxy-α-D-glucopyranosyl)-1D-myo-inositol 3-phosphate + UDP
For diagram of mycothiol biosynthesis, click here
Glossary: mycothiol = 1-O-[2-(N2-acetyl-L-cysteinamido)-2-deoxy-α-D-glucopyranosyl]-1D-myo-inositol
Other name(s): mycothiol glycosyltransferases; MshA; UDP-N-acetyl-D-glucosamine:1D-myo-inositol 3-phosphate α-D-glycosyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:1D-myo-inositol 3-phosphate α-D-glycosyltransferase (configuration-retaining)
Comments: The enzyme, which belongs to the GT-B fold superfamily, catalyses the first dedicated reaction in the biosynthesis of mycothiol [1]. The substrate was initially believed to be inositol, but eventually shown to be D-myo-inositol 3-phosphate [2]. A substantial conformational change occurs upon UDP binding, which generates the binding site for D-myo-inositol 3-phosphate [3].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB
References:
1.  Newton, G.L., Koledin, T., Gorovitz, B., Rawat, M., Fahey, R.C. and Av-Gay, Y. The glycosyltransferase gene encoding the enzyme catalyzing the first step of mycothiol biosynthesis (mshA). J. Bacteriol. 185 (2003) 3476–3479. [DOI] [PMID: 12754249]
2.  Newton, G.L., Ta, P., Bzymek, K.P. and Fahey, R.C. Biochemistry of the initial steps of mycothiol biosynthesis. J. Biol. Chem. 281 (2006) 33910–33920. [DOI] [PMID: 16940050]
3.  Vetting, M.W., Frantom, P.A. and Blanchard, J.S. Structural and enzymatic analysis of MshA from Corynebacterium glutamicum: substrate-assisted catalysis. J. Biol. Chem. 283 (2008) 15834–15844. [DOI] [PMID: 18390549]
[EC 2.4.1.250 created 2010]
 
 
EC 2.4.1.57      
Deleted entry: phosphatidylinositol α-mannosyltransferase. Newer studies have shown that this is catalysed by two independent activities now covered by EC 2.4.1.345, phosphatidyl-myo-inositol α-mannosyl transferase and EC 2.4.1.346, phosphatidyl-myo-inositol dimannoside synthase
[EC 2.4.1.57 created 1972, modified 2003, deleted 2017]
 
 
EC 2.3.1.265     Relevance: 58.8%
Accepted name: phosphatidylinositol dimannoside acyltransferase
Reaction: (1) an acyl-CoA + 2,6-di-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol = CoA + 2-O-(6-O-acyl-α-D-mannosyl)-6-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol
(2) an acyl-CoA + 2-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol = CoA + 2-O-(6-O-acyl-α-D-mannosyl)-1-phosphatidyl-1D-myo-inositol
Other name(s): PIM2 acyltransferase; ptfP1 (gene name)
Systematic name: acyl-CoA:2,6-di-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol acyltransferase
Comments: The enzyme, found in Corynebacteriales, is involved in the biosynthesis of phosphatidyl-myo-inositol mannosides (PIMs).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB
References:
1.  Svetlikova, Z., Barath, P., Jackson, M., Kordulakova, J. and Mikusova, K. Purification and characterization of the acyltransferase involved in biosynthesis of the major mycobacterial cell envelope glycolipid—monoacylated phosphatidylinositol dimannoside. Protein Expr. Purif. 100 (2014) 33–39. [DOI] [PMID: 24810911]
[EC 2.3.1.265 created 2017]
 
 
EC 3.2.1.47      
Deleted entry: galactosylgalactosylglucosylceramidase. Now known to be catalyzed by EC 3.2.1.22, α-galactosidase.
[EC 3.2.1.47 created 1972, modified 2011, deleted 2021]
 
 
EC 3.1.3.57     Relevance: 58.3%
Accepted name: inositol-1,4-bisphosphate 1-phosphatase
Reaction: 1D-myo-inositol 1,4-bisphosphate + H2O = 1D-myo-inositol 4-phosphate + phosphate
For diagram of myo-inositol-phosphate biosynthesis, click here
Other name(s): inositol-polyphosphate 1-phosphatase
Systematic name: 1D-myo-inositol-1,4-bisphosphate 1-phosphohydrolase
Comments: The enzyme acts on inositol 1,4-bisphosphate and inositol 1,3,4-trisphosphate (forming inositol 3,4-bisphosphate) with similar Vmax values for both substrates, but with a five-times higher affinity for the bisphosphate. Does not act on inositol 1-phosphate, inositol 1,4,5-trisphosphate or inositol 1,3,4,5-tetrakisphosphate.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 111070-17-8, 111694-13-4
References:
1.  Berridge, M.J., Dawson, R.M.C., Downes, C.P., Heslop, J.P. and Irvine, R.F. Changes in the levels of inositol phosphates after agonist-dependent hydrolysis of membrane phosphoinositides. Biochem. J. 212 (1983) 473–482. [PMID: 6309146]
2.  Connolly, T.M., Bansal, V.S., Bross, T.E., Irvine, R.F. and Majerus, P.W. The metabolism of tris- and tetraphosphates of inositol by 5-phosphomonoesterase and 3-kinase enzymes. J. Biol. Chem. 262 (1987) 2146–2149. [PMID: 3029066]
3.  Inhorn, R.C. and Majerus, P.W. Inositol polyphosphate 1-phosphatase from calf brain. Purification and inhibition by Li+, Ca2+, and Mn2+. J. Biol. Chem. 262 (1987) 15946–15952. [PMID: 2824473]
[EC 3.1.3.57 created 1989, modified 2002]
 
 
EC 2.4.1.361     Relevance: 58.1%
Accepted name: GDP-mannose:di-myo-inositol-1,3′-phosphate β-1,2-mannosyltransferase
Reaction: 2 GDP-α-D-mannose + bis(myo-inositol) 1,3′-phosphate = 2 GDP + 2-O-(β-D-mannosyl-(1→2)-β-D-mannosyl)-bis(myo-inositol) 1,3′-phosphate (overall reaction)
(1a) GDP-α-D-mannose + bis(myo-inositol) 1,3′-phosphate = GDP + 2-O-(β-D-mannosyl)-bis(myo-inositol) 1,3′-phosphate
(1b) GDP-α-D-mannose + 2-O-(β-D-mannosyl)-bis(myo-inositol) 1,3′-phosphate = GDP + 2-O-(β-D-mannosyl-(1→2)-β-D-mannosyl)-bis(myo-inositol) 1,3′-phosphate
Other name(s): MDIP synthase
Systematic name: GDP-α-D-mannose:bis(myo-inositol)-1,3′-phosphate 2-β-D-mannosyltransferase
Comments: The enzyme from the hyperthermophilic bacterium Thermotoga maritima is involved in the synthesis of the solutes 2-O-(β-D-mannosyl)-bis(myo-inositol) 1,3′-phosphate and 2-O-(β-D-mannosyl-(1→2)-β-D-mannosyl)-bis(myo-inositol) 1,3′-phosphate.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Rodrigues, M.V., Borges, N., Almeida, C.P., Lamosa, P. and Santos, H. A unique β-1,2-mannosyltransferase of Thermotoga maritima that uses di-myo-inositol phosphate as the mannosyl acceptor. J. Bacteriol. 191 (2009) 6105–6115. [PMID: 19648237]
[EC 2.4.1.361 created 2019]
 
 
EC 3.1.3.56     Relevance: 58.1%
Accepted name: inositol-polyphosphate 5-phosphatase
Reaction: (1) D-myo-inositol 1,4,5-trisphosphate + H2O = myo-inositol 1,4-bisphosphate + phosphate
(2) 1D-myo-inositol 1,3,4,5-tetrakisphosphate + H2O = 1D-myo-inositol 1,3,4-trisphosphate + phosphate
For diagram of myo-inositol-phosphate biosynthesis, click here
Other name(s): type I inositol-polyphosphate phosphatase; inositol trisphosphate phosphomonoesterase; InsP3/Ins(1,3,4,5)P4 5-phosphatase; inosine triphosphatase; D-myo-inositol 1,4,5-triphosphate 5-phosphatase; D-myo-inositol 1,4,5-trisphosphate 5-phosphatase; L-myo-inositol 1,4,5-trisphosphate-monoesterase; inositol phosphate 5-phosphomonoesterase; inositol-1,4,5-trisphosphate/1,3,4,5-tetrakisphosphate 5-phosphatase; Ins(1,4,5)P3 5-phosphatase; D-myo-inositol(1,4,5)/(1,3,4,5)-polyphosphate 5-phosphatase; inositol 1,4,5-trisphosphate phosphatase; inositol polyphosphate-5-phosphatase; myo-inositol-1,4,5-trisphosphate 5-phosphatase; inositol-1,4,5-trisphosphate 5-phosphatase
Systematic name: 1D-myo-inositol-1,4,5-trisphosphate 5-phosphohydrolase
Comments: One mammalian isoform is known. This enzyme is distinguished from the family of enzymes classified under EC 3.1.3.36, phosphoinositide 5-phosphatase, by its inability to dephosphorylate inositol lipids.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 106283-14-1
References:
1.  Downes, C.P., Mussat, M.C. and Michell, R.H. The inositol trisphosphate phosphomonoesterase of the human erythrocyte membrane. Biochem. J. 203 (1982) 169–177. [PMID: 6285891]
2.  Erneux, C., Lemos, M., Verjans, B., Vanderhaeghen, P., Delvaux, A. and Dumont, J.E. Soluble and particulate Ins(1,4,5)P3/Ins(1,3,4,5)P4 5-phosphatase in bovine brain. Eur. J. Biochem. 181 (1989) 317–322. [DOI] [PMID: 2540972]
3.  Woscholski, R. and Parker, P.J. Inositol phosphatases: constructive destruction of phosphoinositides and inositol phosphates. In: Cockcroft, S. (Ed.), Biology of Phosphoinositides, Biology of Phosphoinositides, Oxford, 2000, pp. 320–338.
4.  Verjans, B., De Smedt, F., Lecocq, R., Vanweyenberg, V., Moreau, C. and Erneux, C. Cloning and expression in Escherichia coli of a dog thyroid cDNA encoding a novel inositol 1,4,5-trisphosphate 5-phosphatase. Biochem. J. 300 (1994) 85–90. [PMID: 8198557]
[EC 3.1.3.56 created 1989, modified 2002]
 
 
EC 2.4.1.79     Relevance: 58%
Accepted name: globotriaosylceramide 3-β-N-acetylgalactosaminyltransferase
Reaction: UDP-N-acetyl-α-D-galactosamine + α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + N-acetyl-β-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of globotetraosylceramide biosynthesis, click here. For diagram of reaction, click here
Glossary: α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = globotriaosylceramide = Pk antigen
N-acetyl-β-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = globotetraosylceramide = globoside = P antigen
Other name(s): uridine diphosphoacetylgalactosamine-galactosylgalactosylglucosylceramide acetylgalactosaminyltransferase; globoside synthetase; UDP-N-acetylgalactosamine:globotriaosylceramide β-3-N-acetylgalactosaminyltransferase; galactosylgalactosylglucosylceramide β-D-acetylgalactosaminyltransferase; UDP-N-acetylgalactosamine:globotriaosylceramide β1,3-N-acetylgalactosaminyltransferase; globoside synthase; gUDP-N-acetyl-D-galactosamine:D-galactosyl-1,4-D-galactosyl-1,4-D-glucosylceramide β-N-acetyl-D-galactosaminyltransferase; β3GalNAc-T1; UDP-N-acetyl-D-galactosamine:α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosylceramide 3III-β-N-acetyl-D-galactosaminyltransferase; UDP-N-acetyl-D-galactosamine:α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 3III-β-N-acetyl-D-galactosaminyltransferase; UDP-N-acetyl-D-galactosamine:α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide III3-β-N-acetyl-D-galactosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-galactosamine:α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide III3-β-N-acetyl-D-galactosaminyltransferase
Comments: Globoside is a neutral glycosphingolipid in human erythrocytes and has blood-group-P-antigen activity [4]. The enzyme requires a divalent cation for activity, with Mn2+ required for maximal activity [3]. UDP-GalNAc is the only sugar donor that is used efficiently by the enzyme: UDP-Gal and UDP-GlcNAc result in very low enzyme activity [3]. Lactosylceramide, globoside and gangliosides GM3 and GD3 are not substrates [4]. For explanation of the superscripted ’3′ in the systematic name, see GL-5.3.4.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 62213-46-1
References:
1.  Chien, J.-L., Williams, T. and Basu, S. Biosynthesis of a globoside-type glycosphingolipid by a β-N-acetylgalactosaminyltransferase from embryonic chicken brain. J. Biol. Chem. 248 (1973) 1778–1785. [PMID: 4632917]
2.  Ishibashi, T., Kijimoto, S. and Makita, A. Biosynthesis of globoside and Forssman hapten from trihexosylceramide and properties of β-N-acetyl-galactosaminyltransferase of guinea pig kidney. Biochim. Biophys. Acta 337 (1974) 92–106. [DOI] [PMID: 4433547]
3.  Taniguchi, N. and Makita, A. Purification and characterization of UDP-N-acetylgalactosamine: globotriaosylceramide β-3-N-acetylgalactosaminyltransferase, a synthase of human blood group P antigen, from canine spleen. J. Biol. Chem. 259 (1984) 5637–5642. [PMID: 6425294]
4.  Okajima, T., Nakamura, Y., Uchikawa, M., Haslam, D.B., Numata, S.I., Furukawa, K., Urano, T. and Furukawa, K. Expression cloning of human globoside synthase cDNAs. Identification of β3Gal-T3 as UDP-N-acetylgalactosamine:globotriaosylceramide β1,3-N-acetylgalactosaminyltransferase. J. Biol. Chem. 275 (2000) 40498–40503. [DOI] [PMID: 10993897]
[EC 2.4.1.79 created 1976, modified 2006]
 
 
EC 2.4.3.10     Relevance: 57.6%
Accepted name: N-acetylglucosaminide α-(2,6)-sialyltransferase
Reaction: CMP-N-acetyl-β-neuraminate + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R = CMP + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-[N-acetyl-α-neuraminyl-(2→6)]-N-acetyl-β-D-glucosaminyl-R
Other name(s): α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetylglucosaminide 6-α-sialyltransferase; N-acetylglucosaminide (α 2→6)-sialyltransferase; ST6GlcNAc
Systematic name: CMP-N-acetylneuraminate:N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminide N-acetyl-β-D-glucosamine-6-α-N-acetylneuraminyltransferase (configuration-inverting)
Comments: Attaches N-acetylneuraminic acid in α-2,6-linkage to N-acetyl-β-D-glucosamine. The enzyme from rat liver also acts on β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl residues, but more slowly.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Paulson, J.C., Weinstein, J. and de Souza-e-Silva, U. Biosynthesis of a disialylated sequence in N-linked oligosaccharides: identification of an N-acetylglucosaminide (α 2→6)-sialyltransferase in Golgi apparatus from rat liver. Eur. J. Biochem. 140 (1984) 523–530. [PMID: 6547092]
[EC 2.4.3.10 created 2020 as EC 2.4.99.22, transferred 2022 to EC 2.4.3.10]
 
 
EC 2.4.99.22      
Transferred entry: N-acetylglucosaminide α-(2,6)-sialyltransferase. Now EC 2.4.3.10, N-acetylglucosaminide α-(2,6)-sialyltransferase
[EC 2.4.99.22 created 2020, deleted 2022]
 
 
EC 2.4.1.165     Relevance: 57.4%
Accepted name: N-acetylneuraminylgalactosylglucosylceramide β-1,4-N-acetylgalactosaminyltransferase
Reaction: UDP-N-acetyl-α-D-galactosamine + α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of ganglioside biosynthesis, click here
Other name(s): uridine diphosphoacetylgalactosamine-acetylneuraminyl(α2→3)galactosyl(β1→4)glucosyl β1→4-acetylgalactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetylneuraminyl-2,3-α-D-galactosyl-1,4-β-D-glucosylceramide β-1,4-N-acetylgalactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetylneuraminyl-(2→3)-α-D-galactosyl-(1→4)-β-D-glucosyl(1↔1)ceramide 4-β-N-acetylgalactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetylneuraminyl-(2→3)-α-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 4-β-N-acetylgalactosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-galactosamine:α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 4-β-N-acetylgalactosaminyltransferase
Comments: Requires Mn2+. Only substances containing sialic acid residues can act as acceptors; bovine fetuin is the best acceptor tested.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 109136-50-7
References:
1.  Chien, J.-L., Williams, T. and Basu, S. Biosynthesis of a globoside-type glycosphingolipid by a β-N-acetylgalactosaminyltransferase from embryonic chicken brain. J. Biol. Chem. 248 (1973) 1778–1785. [PMID: 4632917]
2.  Piller, F., Blanchard, D., Huet, M. and Cartron, J.-P. Identification of a α-NeuAc-(2-3)-β-D-galactopyranosyl N-acetyl-β-D-galactosaminyltransferase in human kidney. Carbohydr. Res. 149 (1986) 171–184. [DOI] [PMID: 2425965]
3.  Takeya, A., Hosomi, O. and Kogure, T. Identification and characterization of UDP-GalNAc: NeuAc α2-3Gal β1-4Glc(NAc) β1-4(GalNAc to Gal)N-acetylgalactosaminyltransferase in human blood plasma. J. Biochem. (Tokyo) 101 (1987) 251–259. [PMID: 3106337]
[EC 2.4.1.165 created 1989]
 
 
EC 2.4.1.179     Relevance: 57.2%
Accepted name: lactosylceramide β-1,3-galactosyltransferase
Reaction: UDP-α-D-galactose + β-D-galactosyl-(1→4)-β-D-glucosyl-R = UDP + β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-R
For diagram of glycolipid biosynthesis, click here
Glossary: lactosylceramide = β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
Other name(s): uridine diphosphogalactose-lactosylceramide β1→3-galactosyltransferase; UDP-galactose:D-galactosyl-1,4-β-D-glucosyl-R β-1,3-galactosyltransferase; UDP-galactose:D-galactosyl-(1→4)-β-D-glucosyl-R 3-β-galactosyltransferase; UDP-α-D-galactose:D-galactosyl-(1→4)-β-D-glucosyl-R 3-β-galactosyltransferase
Systematic name: UDP-α-D-galactose:β-D-galactosyl-(1→4)-β-D-glucosyl-R 3-β-galactosyltransferase
Comments: R may be an oligosaccharide or a glycolipid; lactose can also act as acceptor, but more slowly. Involved in the elongation of oligosaccharide chains, especially in glycolipids.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 106769-64-6
References:
1.  Bailly, P., Piller, F. and Cartron, J.-P. Characterization and specific assay for a galactoside β-3-galactosyltransferase of human kidney. Eur. J. Biochem. 173 (1988) 417–422. [DOI] [PMID: 3129295]
[EC 2.4.1.179 created 1989]
 
 
EC 2.7.8.34     Relevance: 57.1%
Accepted name: CDP-L-myo-inositol myo-inositolphosphotransferase
Reaction: CDP-1L-myo-inositol + 1L-myo-inositol 1-phosphate = CMP + bis(1L-myo-inositol) 3,1′-phosphate 1-phosphate
For diagram of bis(1L-myo-inositol) 1,3′-phosphate biosynthesis, click here
Glossary: 1L-myo-inositol 1-phosphate = 1D-myo-inositol 3-phosphate
Other name(s): CDP-inositol:inositol-1-phosphate transferase (bifunctional CTP:inositol-1-phosphate cytidylyltransferase/CDP-inositol:inositol-1-phosphate transferase (IPCT/DIPPS)); DIPPS (bifunctional CTP:inositol-1-phosphate cytidylyltransferase/CDP-inositol:inositol-1-phosphate transferase (IPCT/DIPPS))
Systematic name: CDP-1L-myo-inositol:1L-myo-inositol 1-phosphate myo-inositolphosphotransferase
Comments: In many organisms this activity is catalysed by a bifunctional enzyme. The di-myo-inositol-1,3′-phosphate-1′-phosphate synthase domain of the bifunctional EC 2.7.7.74/EC 2.7.8.34 (CTP:inositol-1-phosphate cytidylyltransferase/CDP-inositol:inositol-1-phosphate transferase) uses only 1L-myo-inositol 1-phosphate as an alcohol acceptor, but CDP-glycerol, as well as CDP-1L-myo-inositol and CDP-D-myo-inositol, are recognized as alcohol donors. The enzyme is involved in biosynthesis of bis(1L-myo-inositol) 1,3-phosphate, a widespread organic solute in microorganisms adapted to hot environments.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB
References:
1.  Rodrigues, M.V., Borges, N., Henriques, M., Lamosa, P., Ventura, R., Fernandes, C., Empadinhas, N., Maycock, C., da Costa, M.S. and Santos, H. Bifunctional CTP:inositol-1-phosphate cytidylyltransferase/CDP-inositol:inositol-1-phosphate transferase, the key enzyme for di-myo-inositol-phosphate synthesis in several (hyper)thermophiles. J. Bacteriol. 189 (2007) 5405–5412. [DOI] [PMID: 17526717]
[EC 2.7.8.34 created 2011]
 
 
EC 2.4.3.1     Relevance: 57%
Accepted name: β-galactoside α-(2,6)-sialyltransferase
Reaction: CMP-N-acetyl-β-neuraminate + β-D-galactosyl-R = CMP + N-acetyl-α-neuraminyl-(2→6)-β-D-galactosyl-R
Other name(s): ST6Gal-I; CMP-N-acetylneuraminate:β-D-galactosyl-1,4-N-acetyl-β-D-glucosamine α-2,6-N-acetylneuraminyltransferase; lactosylceramide α-2,6-N-sialyltransferase; CMP-N-acetylneuraminate:β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosamine α-(2→6)-N-acetylneuraminyltransferase; β-galactoside α-2,6-sialyltransferase
Systematic name: CMP-N-acetyl-β-neuraminate:β-D-galactoside α-(2→6)-N-acetylneuraminyltransferase (configuration-inverting)
Comments: The enzyme acts on the terminal non-reducing β-D-galactosyl residue of the oligosaccharide moiety of glycoproteins and glycolipids.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 9075-81-4
References:
1.  Spiro, M.H. and Spiro, R.G. Glycoprotein biosynthesis: studies on thyroglobulin. Thyroid sialyltransferase. J. Biol. Chem. 243 (1968) 6520–6528. [PMID: 5726897]
2.  Hickman, J., Ashwell, G., Morell, A.G., van der Hamer, C.J.A. and Scheinberg, I.H. Physical and chemical studies on ceruloplasmin. 8. Preparation of N-acetylneuraminic acid-1-14C-labeled ceruloplasmin. J. Biol. Chem. 245 (1970) 759–766. [PMID: 4313609]
3.  Bartholomew, B.A., Jourdian, G.W. and Roseman, S. The sialic acids. XV. Transfer of sialic acid to glycoproteins by a sialyltransferase from colostrum. J. Biol. Chem. 248 (1973) 5751–5762. [PMID: 4723915]
4.  Paulson, J.C., Beranek, W.E. and Hill, R.L. Purification of a sialyltransferase from bovine colostrum by affinity chromatography on CDP-agarose. J. Biol. Chem. 252 (1977) 2356–2362. [PMID: 849932]
5.  Schachter, H., Narasimhan, S., Gleeson, P. and Vella, G. Glycosyltransferases involved in elongation of N-glycosidically linked oligosaccharides of the complex or N-acetyllactosamine type. Methods Enzymol. 98 (1983) 98–134. [PMID: 6366476]
6.  Albarracin, I., Lassaga, F.E. and Caputto, R. Purification and characterization of an endogenous inhibitor of the sialyltransferase CMP-N-acetylneuraminate: lactosylceramide α2,6-N-acetylneuraminyltransferase (EC 2.4.99.-). Biochem. J. 254 (1988) 559–565. [PMID: 2460092]
[EC 2.4.3.1 created 1972 as EC 2.4.99.1, modified 1976, modified 1986, modified 2017 (EC 2.4.99.11 created 1992, incorporated 2016), modified 2017, transferred 2021 to EC 2.4.3.1]
 
 
EC 2.4.99.1      
Transferred entry: β-galactoside α-(2,6)-sialyltransferase. Now EC 2.4.3.1, β-galactoside α-(2,6)-sialyltransferase
[EC 2.4.99.1 created 1972, modified 1976, modified 1986, modified 2017 (EC 2.4.99.11 created 1992, incorporated 2017), deleted 2022]
 
 
EC 3.2.1.107     Relevance: 56.9%
Accepted name: protein-glucosylgalactosylhydroxylysine glucosidase
Reaction: [collagen]-(5R)-5-O-[α-D-glucosyl-(1→2)-β-D-galactosyl]-5-hydroxy-L-lysine + H2O = D-glucose + [collagen]-(5R)-5-O-(β-D-galactosyl)-5-hydroxy-L-lysine
Other name(s): PGGHG (gene name); 2-O-α-D-glucopyranosyl-5-O-α-D-galactopyranosylhydroxy-L-lysine glucohydrolase; protein-α-D-glucosyl-1,2-β-D-galactosyl-L-hydroxylysine glucohydrolase; protein-α-D-glucosyl-(1→2)-β-D-galactosyl-L-hydroxylysine glucohydrolase
Systematic name: [collagen]-(5R)-5-O-[α-D-glucosyl-(1→2)-β-D-galactosyl]-5-hydroxy-L-lysine glucohydrolase
Comments: The enzyme specifically hydrolyses glucose from α-D-glucosyl-(1→2)-β-D-galactosyl disaccharide units that are linked to hydroxylysine residues of collagen and collagen-like proteins. Acetylation of the ε-amino group of the glycosylated hydroxylysine abolishes activity.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 72829-45-9
References:
1.  Hamazaki, H. and Hotta, K. Purification and characterization of an α-glucosidase specific for hydroxylysine-linked disaccharide of collagen. J. Biol. Chem. 254 (1979) 9682–9687. [PMID: 385589]
2.  Hamazaki, H. and Hotta, K. Enzymatic hydrolysis of disaccharide unit of collagen. Isolation of 2-O-α-D-glucopyranosyl-O-β-D-galactopyranosyl-hydroxylysine glucohydrolase from rat spleens. Eur. J. Biochem. 111 (1980) 587–591. [DOI] [PMID: 7460918]
3.  Sternberg, M. and Shapiro, R.G. Studies on the catabolism of the hydroxylysine-linked disaccharide units of basement membranes and collagens. Isolation and characterization of a rat kidney α-glucosidase of high specificity. J. Biol. Chem. 254 (1979) 10329–10336. [PMID: 385599]
4.  Hamazaki, H. and Hamazaki, M.H. Catalytic site of human protein-glucosylgalactosylhydroxylysine glucosidase: Three crucial carboxyl residues were determined by cloning and site-directed mutagenesis. Biochem. Biophys. Res. Commun. 469 (2016) 357–362. [DOI] [PMID: 26682924]
[EC 3.2.1.107 created 1984]
 
 
EC 3.1.3.25     Relevance: 56.8%
Accepted name: inositol-phosphate phosphatase
Reaction: myo-inositol phosphate + H2O = myo-inositol + phosphate
For diagram of myo-inositol biosynthesis, click here
Other name(s): myo-inositol-1(or 4)-monophosphatase; inositol 1-phosphatase; L-myo-inositol-1-phosphate phosphatase; myo-inositol 1-phosphatase; inositol phosphatase; inositol monophosphate phosphatase; inositol-1(or 4)-monophosphatase; myo-inositol-1(or 4)-phosphate phosphohydrolase; myo-inositol monophosphatase; myo-inositol-1-phosphatase
Systematic name: myo-inositol-phosphate phosphohydrolase
Comments: Acts on five of the six isomers of myo-inositol phosphate, all except myo-inositol 2-phosphate, but does not act on myo-inositol bearing more than one phosphate group. It also acts on adenosine 2′-phosphate (but not the 3′- or 5′- phosphates), sn-glycerol 3-phosphate and glycerol 2-phosphate. Two isoforms are known [4].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 37184-63-7
References:
1.  Eisenberg, F., Jr. D-Myoinositol 1-phosphate as product of cyclization of glucose 6-phosphate and substrate for a specific phosphatase in rat testis. J. Biol. Chem. 242 (1967) 1375–1382. [PMID: 4290245]
2.  Gee, N.S., Ragan, C.I., Watling, K.J., Aspley, S., Jackson, R.G., Reid, G.G., Gani, D. and Shute, J.K. The purification and properties of myo-inositol monophosphatase from bovine brain. Biochem. J. 249 (1988) 883–889. [PMID: 2833231]
3.  Hallcher, L.M. and Sherman, W.R. The effects of lithium ion and other agents on the activity of myo-inositol-1-phosphatase from bovine brain. J. Biol. Chem. 255 (1980) 10896–10901. [PMID: 6253491]
4.  Yoshikawa, T., Turner, G., Esterling, L.E., Sanders, A.R. and Detera-Wadleigh, S.D. A novel human myo-inositol monophosphatase gene, IMP.18p, maps to a susceptibility region for bipolar disorder. Mol. Psychiatry 2 (1997) 393–397. [PMID: 9322233]
5.  Woscholski, R. and Parker, P.J. Inositol phosphatases: constructive destruction of phosphoinositides and inositol phosphates. In: Cockcroft, S. (Ed.), Biology of Phosphoinositides, Biology of Phosphoinositides, Oxford, 2000, pp. 320–338.
6.  Ackermann, K.E., Gish, B.G., Honchar, M.P. and Sherman, W.R. Evidence that inositol 1-phosphate in brain of lithium-treated rats results mainly from phosphatidylinositol metabolism. Biochem. J. 242 (1987) 517–524. [PMID: 3036092]
[EC 3.1.3.25 created 1972, modified 1990, modified 2002, modified 2004]
 
 
EC 2.7.1.134     Relevance: 56.5%
Accepted name: inositol-tetrakisphosphate 1-kinase
Reaction: ATP + 1D-myo-inositol 3,4,5,6-tetrakisphosphate = ADP + 1D-myo-inositol 1,3,4,5,6-pentakisphosphate
For diagram of myo-inositol-phosphate biosynthesis, click here
Other name(s): 1D-myo-inositol-tetrakisphosphate 1-kinase; inositol-trisphosphate 6-kinase; 1D-myo-inositol-trisphosphate 6-kinase; ATP:1D-myo-inositol-1,3,4-trisphosphate 6-phosphotransferase; inositol-trisphosphate 5-kinase; 1D-myo-inositol-trisphosphate 5-kinase; ATP:1D-myo-inositol-1,3,4-trisphosphate 5-phosphotransferase
Systematic name: ATP:1D-myo-inositol-3,4,5,6-tetrakisphosphate 1-phosphotransferase
Comments: This enzyme also phosphorylates Ins(1,3,4)P3 on O-5 and O-6. The phosphotransfer from ATP to either inositol 1,3,4-trisphosphate or inositol 3,4,5,6-tetrakisphosphate appears to be freely reversible to the extent that the enzyme can act like an inositol polyphosphate phosphatase in the presence of ADP. It can also catalyse an isomerization between Ins(1,3,4,5)P4 and Ins(1,3,4,6)P4 in the presence of ADP. The enzymes from animals and plants also have the activity of EC 2.7.1.159, inositol-1,3,4-trisphosphate 5/6-kinase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 187175-98-0
References:
1.  Stephens, L.R., Hawkins, P.T., Morris, A.J. and Downes, P.C. L-myo-Inositol 1,4,5,6-tetrakisphosphate (3-hydroxy)kinase. Biochem. J. 249 (1988) 283–292. [PMID: 2829850]
2.  Balla, T., Guillemette, G., Baukal, A.J. and Catt, K. Metabolism of inositol 1,3,4-trisphosphate to a new tetrakisphosphate isomer in angiotensin-stimulated adrenal glomerulosa cells. J. Biol. Chem. 262 (1987) 9952–9955. [PMID: 3497156]
3.  Shears, S.B., Parry, J.B., Tang, E.K.Y., Irvine, R.F., Michell, R.H. and Kirk, C.J. Metabolism of D-myo-inositol 1,3,4,5-tetrakisphosphate by rat liver, including the synthesis of a novel isomer of myo-inositol tetrakisphosphate. Biochem. J. 246 (1987) 139–147. [PMID: 2823793]
4.  Shears, S.B. The pathway of myo-inositol 1,3,4-trisphosphate phosphorylation in liver. Identification of myo-inositol 1,3,4-trisphosphate 6-kinase, myo-inositol 1,3,4-trisphosphate 5-kinase, and myo-inositol 1,3,4,6-tetrakisphosphate 5-kinase. J. Biol. Chem. 264 (1989) 19879–19886. [PMID: 2584198]
5.  Yang, X. and Shears, S.B. Multitasking in signal transduction by a promiscuous human Ins(3,4,5,6)P4 1-kinase/Ins(1,3,4)P3 5/6-kinase. Biochem. J. 351 (2000) 551–555. [PMID: 11042108]
6.  Ho, M.W., Yang, X., Carew, M.A., Zhang, T., Hua, L., Kwon, Y.U., Chung, S.K., Adelt, S., Vogel, G., Riley, A.M., Potter, B.V. and Shears, S.B. Regulation of Ins(3,4,5,6)P4 signaling by a reversible kinase/phosphatase. Curr. Biol. 12 (2002) 477–482. [DOI] [PMID: 11909533]
[EC 2.7.1.134 created 1990, (EC 2.7.1.133 created 1989, incorporated 2002, EC 2.7.1.139 created 1992, incorporated 2002), modified 2002]
 
 
EC 2.4.99.6      
Transferred entry: N-acetyllactosaminide α-2,3-sialyltransferase. Now EC 2.4.3.6, N-acetyllactosaminide α-2,3-sialyltransferase
[EC 2.4.99.6 created 1984, modified 1986 (EC 2.4.99.10 created 1986, incorporated 2017), deleted 2022]
 
 
EC 2.4.3.6     Relevance: 56.3%
Accepted name: N-acetyllactosaminide α-2,3-sialyltransferase
Reaction: CMP-N-acetyl-β-neuraminate + β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R = CMP + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R
Other name(s): cytidine monophosphoacetylneuraminate-β-galactosyl(1→4)acetylglucosaminide α2→3-sialyltransferase; α2→3 sialyltransferase (ambiguous); SiaT (ambiguous); CMP-N-acetylneuraminate:β-D-galactosyl-1,4-N-acetyl-D-glucosaminyl-glycoprotein α-2,3-N-acetylneuraminyltransferase; neolactotetraosylceramide α-2,3-sialyltransferase; CMP-N-acetylneuraminate:β-D-galactosyl-(1→4)-N-acetyl-D-glucosaminyl-glycoprotein α-(2→3)-N-acetylneuraminyltransferase
Systematic name: CMP-N-acetyl-β-neuraminate:β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R (2→3)-N-acetyl-α-neuraminyltransferase (configuration-inverting)
Comments: The enzyme recognizes the sequence β-D-galactosyl-(1→4)-N-acetyl-D-glucosaminyl (known as type 2 histo-blood group precursor disaccharide) in non-reducing termini of glycan moieties in glycoproteins and glycolipids. The enzyme from chicken brain was shown to act on neolactotetraosylceramide, producing ganglioside LM1 [2].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 77537-85-0
References:
1.  Van den Eijnden, D.H. and Schiphorst, W.E.C.M. Detection of β-galactosyl(1→4)N-acetylglucosaminide α(2→3)-sialyltransferase activity in fetal calf liver and other tissues. J. Biol. Chem. 256 (1981) 3159–3162. [PMID: 7204397]
2.  Basu, M., Basu, S., Stoffyn, A. and Stoffyn, P. Biosynthesis in vitro of sialyl(α2-3)neolactotetraosylceramide by a sialyltransferase from embryonic chicken brain. J. Biol. Chem. 257 (1982) 12765–12769. [PMID: 7130178]
[EC 2.4.3.6 created 1984 as EC 2.4.99.6, modified 1986 (EC 2.4.99.10 created 1986, incorporated 2017), transferred 2022 to EC 2.4.3.6]
 
 
EC 2.4.1.135     Relevance: 55.6%
Accepted name: galactosylgalactosylxylosylprotein 3-β-glucuronosyltransferase
Reaction: UDP-α-D-glucuronate + [protein]-3-O-(β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine = UDP + [protein]-3-O-(β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine
For diagram of heparan and chondroitin biosynthesis (early stages), click here
Glossary: [protein]-3-O-(β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine = [protein]-3-O-(β-D-glucuronosyl-(1→3)-β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine
Other name(s): glucuronosyltransferase I; uridine diphosphate glucuronic acid:acceptor glucuronosyltransferase; UDP-glucuronate:3-β-D-galactosyl-4-β-D-galactosyl-O-β-D-xylosyl-protein D-glucuronosyltransferase; UDP-glucuronate:3-β-D-galactosyl-4-β-D-galactosyl-O-β-D-xylosylprotein D-glucuronosyltransferase
Systematic name: UDP-α-D-glucuronate:[protein]-3-O-(β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine D-glucuronosyltransferase (configuration-inverting)
Comments: Involved in the biosynthesis of the linkage region of glycosaminoglycan chains as part of proteoglycan biosynthesis (chondroitin, dermatan and heparan sulfates). Requires Mn2+.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 227184-75-0
References:
1.  Helting, J. and Roden, L. Biosynthesis of chondroitin sulfate. II. Glucuronosyl transfer in the formation of the carbohydrate-protein linkage region. J. Biol. Chem. 244 (1969) 2799–2805. [PMID: 5770003]
2.  Helting, T. Biosynthesis of heparin. Solubilization and partial purification of uridine diphosphate glucuronic acid: acceptor glucuronosyltransferase from mouse mastocytoma. J. Biol. Chem. 247 (1972) 4327–4332. [PMID: 4260846]
3.  Kitagawa, H., Tone, Y., Tamura, J., Neumann, K.W., Ogawa, T., Oka, S., Kawasaki, T. and Sugahara, K. Molecular cloning and expression of glucuronyltransferase I involved in the biosynthesis of the glycosaminoglycan-protein linkage region of proteoglycans. J. Biol. Chem. 273 (1998) 6615–6618. [DOI] [PMID: 9506957]
[EC 2.4.1.135 created 1984, modified 2002, modified 2016]
 
 
EC 2.4.1.247     Relevance: 55.3%
Accepted name: β-D-galactosyl-(1→4)-L-rhamnose phosphorylase
Reaction: β-D-galactosyl-(1→4)-L-rhamnose + phosphate = L-rhamnose + α-D-galactose 1-phosphate
Other name(s): D-galactosyl-β1→4-L-rhamnose phosphorylase; GalRhaP
Systematic name: β-D-galactosyl-(1→4)-L-rhamnose:phosphate 1-α-D-galactosyltransferase
Comments: The enzyme from Clostridium phytofermentans is also active towards towards β-D-galactosyl derivatives of L-mannose, L-lyxose, D-glucose, 2-deoxy-D-glucose, and D-galactose in this order. Differs from 1,3-β-galactosyl-N-acetylhexosamine phosphorylase (EC 2.4.1.211) in being active towards L-rhamnose and inactive towards N-acetyl hexosamine derivatives.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 1236189-79-9
References:
1.  Nakajima, M., Nishimoto, M. and Kitaoka, M. Characterization of three β-galactoside phosphorylases from Clostridium phytofermentans: discovery of D-galactosyl-β1→4-L-rhamnose phosphorylase. J. Biol. Chem. 284 (2009) 19220–19227. [DOI] [PMID: 19491100]
[EC 2.4.1.247 created 2009]
 
 
EC 2.7.7.74     Relevance: 55.1%
Accepted name: 1L-myo-inositol 1-phosphate cytidylyltransferase
Reaction: CTP + 1L-myo-inositol 1-phosphate = diphosphate + CDP-1L-myo-inositol
For diagram of bis(1L-myo-inositol) 1,3′-phosphate biosynthesis, click here
Glossary: 1L-myo-inositol 1-phosphate = 1D-myo-inositol 3-phosphate
Other name(s): CTP:inositol-1-phosphate cytidylyltransferase (bifunctional CTP:inositol-1-phosphate cytidylyltransferase/CDP-inositol:inositol-1-phosphate transferase (IPCT/DIPPS)); IPCT (bifunctional CTP:inositol-1-phosphate cytidylyltransferase/CDP-inositol:inositol-1-phosphate transferase (IPCT/DIPPS)); L-myo-inositol-1-phosphate cytidylyltransferase
Systematic name: CTP:1L-myo-inositol 1-phosphate cytidylyltransferase
Comments: In many organisms this activity is catalysed by a bifunctional enzyme. The cytidylyltransferase domain of the bifunctional EC 2.7.7.74/EC 2.7.8.34 (CTP:inositol-1-phosphate cytidylyltransferase/CDP-inositol:inositol-1-phosphate transferase) is absolutely specific for CTP and 1L-myo-inositol 1-phosphate. The enzyme is involved in biosynthesis of bis(1L-myo-inositol) 1,3′-phosphate, a widespread organic solute in microorganisms adapted to hot environments.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB
References:
1.  Rodrigues, M.V., Borges, N., Henriques, M., Lamosa, P., Ventura, R., Fernandes, C., Empadinhas, N., Maycock, C., da Costa, M.S. and Santos, H. Bifunctional CTP:inositol-1-phosphate cytidylyltransferase/CDP-inositol:inositol-1-phosphate transferase, the key enzyme for di-myo-inositol-phosphate synthesis in several (hyper)thermophiles. J. Bacteriol. 189 (2007) 5405–5412. [DOI] [PMID: 17526717]
[EC 2.7.7.74 created 2011]
 
 
EC 2.4.1.65     Relevance: 54.7%
Accepted name: 3-galactosyl-N-acetylglucosaminide 4-α-L-fucosyltransferase
Reaction: GDP-β-L-fucose + β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R = GDP + β-D-galactosyl-(1→3)-[α-L-fucosyl-(1→4)]-N-acetyl-β-D-glucosaminyl-R
For diagram of reaction, click here
Other name(s): (Lea)-dependent (α-3/4)-fucosyltransferase; α(1,3/1,4) fucosyltransferase III; α-(1→4)-L-fucosyltransferase; α-4-L-fucosyltransferase; β-acetylglucosaminylsaccharide fucosyltransferase; FucT-II; Lewis α-(1→3/4)-fucosyltransferase; Lewis blood group α-(1→3/4)-fucosyltransferase; Lewis(Le) blood group gene-dependent α-(1→3/4)-L-fucosyltransferase; blood group Lewis α-4-fucosyltransferase; blood-group substance Lea-dependent fucosyltransferase; guanosine diphosphofucose-β-acetylglucosaminylsaccharide 4-α-L-fucosyltransferase; guanosine diphosphofucose-glycoprotein 4-α-L-fucosyltransferase; guanosine diphosphofucose-glycoprotein 4-α-fucosyltransferase; 3-α-galactosyl-N-acetylglucosaminide 4-α-L-fucosyltransferase; GDP-β-L-fucose:3-β-D-galactosyl-N-acetyl-D-glucosaminyl-R 4I-α-L-fucosyltransferase; GDP-L-fucose:3-β-D-galactosyl-N-acetyl-D-glucosaminyl-R 4I-α-L-fucosyltransferase
Systematic name: GDP-β-L-fucose:β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R 4I-α-L-fucosyltransferase (configuration-inverting)
Comments: This enzyme is the product of the Lewis blood group gene. Normally acts on a glycoconjugate where R (see reaction) is a glycoprotein or glycolipid. Although it is a 4-fucosyltransferase, it has a persistent 3-fucosyltransferase activity towards the glucose residue in free lactose. This enzyme fucosylates on O-4 of an N-acetylglucosamine that carries a galactosyl group on O-3, unlike EC 2.4.1.152, 4-galactosyl-N-acetylglucosaminide 3-α-L-fucosyltransferase, which fucosylates on O-3 of an N-acetylglucosamine that carries a galactosyl group on O-4. Enzymes catalysing the 4-α-fucosylation of the GlcNAc in β-D-Gal-(1→3)-β-GlcNAc sequences (with some activity also as 3-α-fucosyltransferases) are present in plants, where the function in vivo is the modification of N-glycans. In addition, the fucTa gene of Helicobacter strain UA948 encodes a fucosyltransferase with both 3-α- and 4-α-fucosyltransferase activities.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 37277-69-3
References:
1.  Prieels, J.-P., Monnom, D., Dolmans, M., Beyer, T.A. and Hill, R.L. Co-purification of the Lewis blood group N-acetylglucosaminide α1→4 fucosyltransferase and an N-acetylglucosaminide α1→3 fucosyltransferase from human milk. J. Biol. Chem. 256 (1981) 10456–10463. [PMID: 7287719]
2.  Rasko, D.A., Wang, G., Palcic, M.M. and Taylor, D.E. Cloning and characterization of the α(1,3/4) fucosyltransferase of Helicobacter pylori. J. Biol. Chem. 275 (2000) 4988–4994. [DOI] [PMID: 10671538]
3.  Wilson, I.B.H. Identification of a cDNA encoding a plant Lewis-type α1,4-fucosyltransferase. Glycoconj. J. 18 (2001) 439–447. [PMID: 12084979]
4.  Ma, B., Wang, G., Palcic, M.M., Hazes, B. and Taylor, D.E. C-terminal amino acids of Helicobacter pylori α1,3/4 fucosyltransferases determine type I and type II transfer. J. Biol. Chem. 278 (2003) 21893–21900. [DOI] [PMID: 12676935]
[EC 2.4.1.65 created 1972, modified 2001, modified twice 2002]
 
 
EC 3.1.3.66     Relevance: 54.5%
Accepted name: phosphatidylinositol-3,4-bisphosphate 4-phosphatase
Reaction: 1-phosphatidyl-myo-inositol 3,4-bisphosphate + H2O = 1-phosphatidyl-1D-myo-inositol 3-phosphate + phosphate
For diagram of 1-phosphatidyl-myo-inositol metabolism, click here
Glossary: inositol 3-phosphate = Ins-3-P
inositol 1,3-bisphosphate = Ins(1,3)P2
inositol 3,4-bisphosphate = Ins(3,4)P2
inositol 1,3,4-trisphosphate = Ins(1,3,4)P3
1-phosphatidyl-1D-myo-inositol 3-phosphate = PtdIns3P
1-phosphatidyl-1D-myo-inositol 4-phosphate = PtdIns4P
Other name(s): inositol-3,4-bisphosphate 4-phosphatase; D-myo-inositol-3,4-bisphosphate 4-phosphohydrolase; phosphoinositide 4-phosphatase; inositol polyphosphate 4-phosphatase; inositol polyphosphate 4-phosphatase type II
Systematic name: 1-phosphatidyl-1D-myo-inositol-3,4-bisphosphate 4-phosphohydrolase
Comments: Mg2+-independent. This enzyme still works when the 2,3-bis(acyloxy)propyl group is removed, i.e., it hydrolyses Ins(1,3,4)P3 to Ins(1,3)P2. It also converts Ins(3,4)P2 into Ins-3-P.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 123644-80-4
References:
1.  Howell, S., Barnaby, R.J., Rowe, T., Ragan, C.I. and Gee, N.S. Evidence for at least four different inositol bisphosphatases in bovine brain. Eur. J. Biochem. 183 (1989) 169–172. [DOI] [PMID: 2546770]
2.  Norris, F.A., Auethavekiat, V. and Majerus, P.W. The isolation and characterization of cDNA encoding human and rat brain inositol polyphosphate 4-phosphatase. J. Biol. Chem. 270 (1995) 16128–16133. [DOI] [PMID: 7608176]
3.  Norris, F.A., Atkins, R.C. and Majerus, P.W. The cDNA cloning and characterization of inositol polyphosphate 4-phosphatase type II. Evidence for conserved alternative splicing in the 4-phosphatase family. J. Biol. Chem. 272 (1997) 23859–23864. [DOI] [PMID: 9295334]
[EC 3.1.3.66 created 1992, modified 2002]
 
 
EC 2.7.1.228     Relevance: 54.4%
Accepted name: mannosyl-inositol-phosphoceramide inositolphosphotransferase
Reaction: 1-phosphatidyl-1D-myo-inositol + a (4R)-4-hydroxy-N-[(2R)-2-hydroxy-very-long-chain-acyl]-1-O-{[6-O-(α-D-mannosyl)-1D-myo-inositol-1-O-yl]hydroxyphosphoryl}sphinganine = 1,2-diacyl-sn-glycerol + a (4R)-4-hydroxy-N-[(2R)-2-hydroxy-very-long-chain-acyl]-1-O-[(6-O-{6-O-[(1D-myo-inositol-1-O-yl)hydroxyphosphoryl]-α-D-mannosyl}-1D-myo-inositol-1-O-yl)hydroxyphosphoryl]sphinganine
Glossary: a (4R)-4-hydroxy-N-[(2R)-2-hydroxy-very-long-chain-acyl]-1-O-{[6-O-(α-D-mannosyl)-1D-myo-inositol-1-O-yl]hydroxyphosphoryl}sphinganine = a very-long-chain mannosylinositol phospho-α-hydroxyphytoceramide = MIPC
a (4R)-4-hydroxy-N-[(2R)-2-hydroxy-very-long-chain-acyl]-1-O-[(6-O-{6-O-[(1D-myo-inositol-1-O-yl)hydroxyphosphoryl]-α-D-mannosyl}-1D-myo-inositol-1-O-yl)hydroxyphosphoryl]sphinganine = a very-long-chain mannosyl-diphosphoinositol-α-hydroxyphytoceramide = MIP2C
Other name(s): IPT1 (gene name)
Systematic name: 1-phosphatidyl-1D-myo-inositol:(4R)-4-hydroxy-N-[(2R)-2-hydroxy-very-long-chain-acyl]-1-O-{[6-O-(α-D-mannosyl)-1D-myo-inositol-1-O-yl]hydroxyphosphoryl}sphinganine phosphoinositoltransferase
Comments: This enzyme catalyses the ultimate reaction in the yeast sphingolipid biosynthesis pathway. It transfers a second phosphoinositol group to mannosyl-inositol-phospho-α-hydroxyphytoceramide (MIPC), forming the final and most abundant yeast sphingolipid, mannosyl-diphosphoinositol-ceramide (MIP2C).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Dickson, R.C., Nagiec, E.E., Wells, G.B., Nagiec, M.M. and Lester, R.L. Synthesis of mannose-(inositol-P)2-ceramide, the major sphingolipid in Saccharomyces cerevisiae, requires the IPT1 (YDR072c) gene. J. Biol. Chem. 272 (1997) 29620–29625. [DOI] [PMID: 9368028]
[EC 2.7.1.228 created 2019]
 
 
EC 3.1.1.26     Relevance: 54%
Accepted name: galactolipase
Reaction: 1,2-diacyl-3-β-D-galactosyl-sn-glycerol + 2 H2O = 3-β-D-galactosyl-sn-glycerol + 2 carboxylates
Other name(s): galactolipid lipase; polygalactolipase; galactolipid acylhydrolase
Systematic name: 1,2-diacyl-3-β-D-galactosyl-sn-glycerol acylhydrolase
Comments: Also acts on 2,3-di-O-acyl-1-O-(6-O-α-D-galactosyl-β-D-galactosyl)-D-glycerol, and phosphatidylcholine and other phospholipids.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 37278-40-3
References:
1.  Helmsing, P.J. Purification and properties of galactolipase. Biochim. Biophys. Acta 178 (1969) 519–533. [DOI] [PMID: 5784904]
2.  Hirayama, O., Matsuda, H., Takeda, H., Maenaka, K. and Takatsuka, H. Purification and properties of a lipid acyl-hydrolase from potato tubers. Biochim. Biophys. Acta 384 (1975) 127–137. [DOI] [PMID: 236765]
[EC 3.1.1.26 created 1972]
 
 
EC 2.4.1.198     Relevance: 53.8%
Accepted name: phosphatidylinositol N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + 1-phosphatidyl-1D-myo-inositol = UDP + 6-(N-acetyl-α-D-glucosaminyl)-1-phosphatidyl-1D-myo-inositol
For diagram of glycosylphosphatidyl-myo-inositol biosynthesis, click here
Glossary: 1-phosphatidyl-1D-myo-inositol = PtdIns
Other name(s): UDP-N-acetyl-D-glucosamine:phosphatidylinositol N-acetyl-D-glucosaminyltransferase; uridine diphosphoacetylglucosamine α1,6-acetyl-D-glucosaminyltransferase; UDP-N-acetyl-D-glucosamine:1-phosphatidyl-1D-myo-inositol 6-(N-acetyl-α-D-glucosaminyl)transferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:1-phosphatidyl-1D-myo-inositol 6-(N-acetyl-α-D-glucosaminyl)transferase (configuration-retaining)
Comments: Involved in the first step of glycosylphosphatidylinositol (GPI) anchor formation in all eukaryotes. In mammalian cells, the enzyme is composed of at least five subunits (PIG-A, PIG-H, PIG-C, GPI1 and PIG-P). PIG-A subunit is the catalytic subunit. In some species, the long-chain acyl groups of the phosphatidyl group are partly replaced by long-chain alkyl or alk-1-enyl groups.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 144388-35-2
References:
1.  Doering, T.L., Masteron, W.J., Englund, P.T. and Hart, G.W. Biosynthesis of the glycosyl phosphatidylinositol membrane anchor of the trypanosome variant surface glycoprotein. Origin of the non-acetylated glucosamine. J. Biol. Chem. 264 (1989) 11168–11173. [PMID: 2525555]
2.  Watanabe, R., Inoue, N., Westfall, B., Taron, C.H., Orlean, P., Takeda, J. and Kinoshita, T. The first step of glycosylphosphatidylinositol biosynthesis is mediated by a complex of PIG-A, PIG-H , PIG-C and GPI1. EMBO J. 17 (1998) 877–885. [DOI] [PMID: 9463366]
3.  Watanabe, R., Murakami, Y., Marmor, M.D., Inoue, N., Maeda, Y., Hino, J., Kangawa, K., Julius, M. and Kinoshita, T. Initial enzyme for glycosylphosphatidylinositol biosynthesis requires PIG-P and is regulated by DPM2. EMBO J. 19 (2000) 4402–4411. [DOI] [PMID: 10944123]
[EC 2.4.1.198 created 1992, modified 2002]
 
 
EC 1.1.1.369     Relevance: 53.6%
Accepted name: D-chiro-inositol 1-dehydrogenase
Reaction: 1D-chiro-inositol + NAD+ = 2D-2,3,5/4,6-pentahydroxycyclohexanone + NADH + H+
For diagram of inositol catabolism, click here
Glossary: 1D-chiro-inositol = 1,2,4/3,5,6-cyclohexane-1,2,3,4,5,6-hexol
Other name(s): DCI 1-dehydrogenase; IolG
Systematic name: 1D-chiro-inositol:NAD+ 1-oxidoreductase
Comments: The enzyme, found in the bacterium Bacillus subtilis, also catalyses the reaction of EC 1.1.1.18, inositol 2-dehydrogenase, and can also use D-glucose and D-xylose. It shows trace activity with D-ribose and D-fructose [1]. It is part of a myo-inositol/D-chiro-inositol degradation pathway leading to acetyl-CoA.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB
References:
1.  Ramaley, R., Fujita, Y. and Freese, E. Purification and properties of Bacillus subtilis inositol dehydrogenase. J. Biol. Chem. 254 (1979) 7684–7690. [PMID: 112095]
2.  Yoshida, K., Yamaguchi, M., Morinaga, T., Ikeuchi, M., Kinehara, M. and Ashida, H. Genetic modification of Bacillus subtilis for production of D-chiro-inositol, an investigational drug candidate for treatment of type 2 diabetes and polycystic ovary syndrome. Appl. Environ. Microbiol. 72 (2006) 1310–1315. [DOI] [PMID: 16461681]
[EC 1.1.1.369 created 2014]
 
 
EC 2.7.1.159     Relevance: 53.5%
Accepted name: inositol-1,3,4-trisphosphate 5/6-kinase
Reaction: (1) ATP + 1D-myo-inositol 1,3,4-trisphosphate = ADP + 1D-myo-inositol 1,3,4,5-tetrakisphosphate
(2) ATP + 1D-myo-inositol 1,3,4-trisphosphate = ADP + 1D-myo-inositol 1,3,4,6-tetrakisphosphate
Other name(s): Ins(1,3,4)P3 5/6-kinase; inositol trisphosphate 5/6-kinase
Systematic name: ATP:1D-myo-inositol 1,3,4-trisphosphate 5-phosphotransferase
Comments: In humans, this enzyme, along with EC 2.7.1.127 (inositol-trisphosphate 3-kinase), EC 2.7.1.140 (inositol-tetrakisphosphate 5-kinase) and EC 2.7.1.158 (inositol pentakisphosphate 2-kinase) is involved in the production of inositol hexakisphosphate (InsP6). InsP6 is involved in many cellular processes, including mRNA export from the nucleus [2]. Yeasts do not have this enzyme, so produce InsP6 from Ins(1,4,5)P3 by the actions of EC 2.7.1.151 (inositol-polyphosphate multikinase) and EC 2.7.1.158 (inositol-pentakisphosphate 2-kinase) [2]. The enzymes from animals and plants also have the activity of EC 2.7.1.134, inositol-tetrakisphosphate 1-kinase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 288307-53-9
References:
1.  Wilson, M.P. and Majerus, P.W. Isolation of inositol 1,3,4-trisphosphate 5/6-kinase, cDNA cloning and expression of the recombinant enzyme. J. Biol. Chem. 271 (1996) 11904–11910. [DOI] [PMID: 8662638]
2.  Verbsky, J.W., Chang, S.C., Wilson, M.P., Mochizuki, Y. and Majerus, P.W. The pathway for the production of inositol hexakisphosphate in human cells. J. Biol. Chem. 280 (2005) 1911–1920. [DOI] [PMID: 15531582]
3.  Miller, G.J., Wilson, M.P., Majerus, P.W. and Hurley, J.H. Specificity determinants in inositol polyphosphate synthesis: crystal structure of inositol 1,3,4-trisphosphate 5/6-kinase. Mol. Cell. 18 (2005) 201–212. [DOI] [PMID: 15837423]
[EC 2.7.1.159 created 2006]
 
 
EC 2.7.8.11     Relevance: 53.2%
Accepted name: CDP-diacylglycerol—inositol 3-phosphatidyltransferase
Reaction: CDP-diacylglycerol + myo-inositol = CMP + 1-phosphatidyl-1D-myo-inositol
For diagram of 1-phosphatidyl-myo-inositol metabolism, click here
Glossary: 1-phosphatidyl-1D-myo-inositol = PtdIns
Other name(s): CDP-diglyceride-inositol phosphatidyltransferase; phosphatidylinositol synthase; CDP-diacylglycerol-inositol phosphatidyltransferase; CDP-diglyceride:inositol transferase; cytidine 5′-diphospho-1,2-diacyl-sn-glycerol:myo-inositol 3-phosphatidyltransferase; CDP-DG:inositol transferase; cytidine diphosphodiglyceride-inositol phosphatidyltransferase; CDP-diacylglycerol:myo-inositol-3-phosphatidyltransferase; CDP-diglyceride-inositol transferase; cytidine diphosphoglyceride-inositol phosphatidyltransferase; cytidine diphosphoglyceride-inositol transferase
Systematic name: CDP-diacylglycerol:myo-inositol 3-phosphatidyltransferase
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9027-01-4
References:
1.  Bleasdale, J.E., Wallis, P., MacDonald, P.C. and Johnston, J.M. Characterization of the forward and reverse reactions catalyzed by CDP-diacylglycerol:inositol transferase in rabbit lung tissue. Biochim. Biophys. Acta 575 (1979) 135–147. [DOI] [PMID: 41587]
2.  Prottey, C. and Hawthorne, J.N. The biosynthesis of phosphatidic acid and phosphatidylinositol in mammalian pancreas. Biochem. J. 105 (1967) 379–392. [PMID: 4293959]
3.  Salway, J.G., Harewood, J.L., Kai, M., White, G.L. and Hawthorne, J.N. Enzymes of phosphoinositide metabolism during rat brain development. J. Neurochem. 15 (1968) 221–226. [DOI] [PMID: 4295616]
4.  Takenawa, T. and Egawa, K. CDP-diglyceride:inositol transferase from rat liver. Purification and properties. J. Biol. Chem. 252 (1977) 5419–5423. [PMID: 18462]
[EC 2.7.8.11 created 1972, modified 1976]
 
 
EC 2.1.1.129     Relevance: 53.1%
Accepted name: inositol 4-methyltransferase
Reaction: S-adenosyl-L-methionine + myo-inositol = S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol
For diagram of reaction, click here
Other name(s): myo-inositol 4-O-methyltransferase; S-adenosyl-L-methionine:myo-inositol 4-O-methyltransferase; myo-inositol 6-O-methyltransferase
Systematic name: S-adenosyl-L-methionine:1D-myo-inositol 4-methyltransferase
Comments: The enzyme from the rice bean Vigna umbellata (Fabaceae) is highly specific for S-adenosyl-L-methionine. The enzyme also methylates 1L-1,2,4/3,5-cyclohexanepentol, 2,4,6/3,5-pentahydroxycyclohexanone, D,L-2,3,4,6/5-pentacyclohexanone and 2,2′-anhydro-2-C-hydroxymethyl-myo-inositol, but at lower rates than that of myo-inositol.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 169277-48-9
References:
1.  Vernon, D.M., Bohnert, H.J. A novel methyl transferase induced by osmotic stress in the facultative halophyte Mesembryanthemum crystallinum. EMBO J. 11 (1992) 2077–2085. [PMID: 1600940]
2.  Wanek, W. and Richter, A. Purification and characterization of myo-inositol 6-O-methyltransferase from Vigna umbellata Ohwi et Ohashi. Planta 197 (1995) 427–434.
[EC 2.1.1.129 created 1999 (EC 2.1.1.134 created 1999, incorporated 2002), modified 2002]
 
 
EC 3.1.3.64     Relevance: 53.1%
Accepted name: phosphatidylinositol-3-phosphatase
Reaction: 1-phosphatidyl-1D-myo-inositol 3-phosphate + H2O = 1-phosphatidyl-1D-myo-inositol + phosphate
For diagram of 1-phosphatidyl-myo-inositol metabolism, click here
Glossary: inositol 1-phosphate = Ins-1-P
inositol 1,3-bisphosphate = Ins(1,3)P2
1-phosphatidyl-1D-myo-inositol = PtdIns
1-phosphatidyl-1D-myo-inositol 3-phosphate = PtdIns3P
Other name(s): inositol-1,3-bisphosphate 3-phosphatase; inositol 1,3-bisphosphate phosphatase; inositol-polyphosphate 3-phosphatase; D-myo-inositol-1,3-bisphosphate 3-phosphohydrolase; phosphatidyl-3-phosphate 3-phosphohydrolase
Systematic name: 1-phosphatidyl-1D-myo-inositol-3-phosphate 3-phosphohydrolase
Comments: This enzyme still works when the 2,3-bis(acyloxy)propyl group is removed, i.e., it hydrolyses Ins(1,3)P2 to Ins-1-P.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 124248-47-1
References:
1.  Lips, D.L. and Majerus, P.W. The discovery of a 3-phosphomonoesterase that hydrolyzes phosphatidylinositol 3-phosphate in NIH 3T3 cells. J. Biol. Chem. 264 (1989) 19911–19915. [PMID: 2555336]
2.  Caldwell, K.K., Lips, D.L., Bansal, V.S. and Majerus, P.W. Isolation and characterization of two 3-phosphatases that hydrolyze both phosphatidylinositol 3-phosphate and inositol 1,3-bisphosphate. J. Biol. Chem. 266 (1991) 18378–18386. [PMID: 1655747]
[EC 3.1.3.64 created 1992, [EC 3.1.3.65 created 1992, incorporated 2002], modified 2002]]
 
 
EC 2.7.1.127     Relevance: 52.9%
Accepted name: inositol-trisphosphate 3-kinase
Reaction: ATP + 1D-myo-inositol 1,4,5-trisphosphate = ADP + 1D-myo-inositol 1,3,4,5-tetrakisphosphate
For diagram of myo-inositol-phosphate biosynthesis, click here
Other name(s): 1D-myo-inositol-trisphosphate 3-kinase; Ins(1,4,5)P3 3-kinase
Systematic name: ATP:1D-myo-inositol-1,4,5-trisphosphate 3-phosphotransferase
Comments: Activated by Ca2+. Three isoforms have been shown to exist [3].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 106283-10-7
References:
1.  Hansen, C.A., Mah, S. and Williamson, J.R. Formation and metabolism of inositol 1,3,4,5-tetrakisphosphate in liver. J. Biol. Chem. 261 (1986) 8100–8103. [PMID: 3487541]
2.  Irvine, R.F., Letcher, A.J., Heslop, J.P. and Berridge, M.J. The inositol tris/tetrakisphosphate pathway - demonstration of Ins(1,4,5)P3 3-kinase activity in animal tissues. Nature 320 (1986) 631–634. [DOI] [PMID: 3010126]
3.  Irvine, R.F. and Schell, M.J. Back in the water - the return of the inositol phosphates. Nat. Rev. Mol. Cell. Biol. 2 (2001) 327–338. [DOI] [PMID: 11331907]
[EC 2.7.1.127 created 1989, modified 2002]
 
 
EC 2.7.1.151     Relevance: 52.8%
Accepted name: inositol-polyphosphate multikinase
Reaction: 2 ATP + 1D-myo-inositol 1,4,5-trisphosphate = 2 ADP + 1D-myo-inositol 1,3,4,5,6-pentakisphosphate (overall reaction)
(1a) ATP + 1D-myo-inositol 1,4,5-trisphosphate = ADP + 1D-myo-inositol 1,4,5,6-tetrakisphosphate
(1b) ATP + 1D-myo-inositol 1,4,5,6-tetrakisphosphate = ADP + 1D-myo-inositol 1,3,4,5,6-pentakisphosphate
For diagram of myo-inositol-phosphate metabolism, click here
Other name(s): IpK2; IP3/IP4 6-/3-kinase; IP3/IP4 dual-specificity 6-/3-kinase; IpmK; ArgRIII; AtIpk2α; AtIpk2β; inositol polyphosphate 6-/3-/5-kinase
Systematic name: ATP:1D-myo-inositol-1,4,5-trisphosphate 6-phosphotransferase
Comments: This enzyme also phosphorylates Ins(1,4,5)P3 to Ins(1,3,4,5)P4, Ins(1,3,4,5)P4 to Ins(1,3,4,5,6)P5, and Ins(1,3,4,5,6)P4 to Ins(PP)P4, isomer unknown. The enzyme from the plant Arabidopsis thaliana can also phosphorylate Ins(1,3,4,6)P4 and Ins(1,2,3,4,6)P5 at the D-5-position to produce 1,3,4,5,6-pentakisphosphate and inositol hexakisphosphate (InsP6), respectively [3]. Yeast produce InsP6 from Ins(1,4,5)P3 by the actions of this enzyme and EC 2.7.1.158, inositol-pentakisphosphate 2-kinase [4].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9077-69-4
References:
1.  Saiardi, A., Erdjument-Bromage, H., Snowman, A.M., Tempst, P. and Snyder, S.H. Synthesis of diphosphoinositol pentakisphosphate by a newly identified family of higher inositol polyphosphate kinases. Curr. Biol. 9 (1999) 1323–1326. [DOI] [PMID: 10574768]
2.  Odom, A.R., Stahlberg, A., Wente, S.R. and York, J.D. A role for nuclear inositol 1,4,5-trisphosphate kinase in transcriptional control. Science 287 (2000) 2026–2029. [DOI] [PMID: 10720331]
3.  Stevenson-Paulik, J., Odom, A.R. and York, J.D. Molecular and biochemical characterization of two plant inositol polyphosphate 6-/3-/5-kinases. J. Biol. Chem. 277 (2002) 42711–42718. [DOI] [PMID: 12226109]
4.  Verbsky, J.W., Chang, S.C., Wilson, M.P., Mochizuki, Y. and Majerus, P.W. The pathway for the production of inositol hexakisphosphate in human cells. J. Biol. Chem. 280 (2005) 1911–1920. [DOI] [PMID: 15531582]
[EC 2.7.1.151 created 2002, modified 2006]
 
 
EC 2.4.1.134     Relevance: 52.2%
Accepted name: galactosylxylosylprotein 3-β-galactosyltransferase
Reaction: UDP-α-D-galactose + [protein]-3-O-(β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine = UDP + [protein]-3-O-(β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine
For diagram of heparan and chondroitin biosynthesis (early stages), click here
Other name(s): galactosyltransferase II; uridine diphosphogalactose-galactosylxylose galactosyltransferase; UDP-galactose:4-β-D-galactosyl-O-β-D-xylosylprotein 3-β-D-galactosyltransferase; UDP-α-D-galactose:4-β-D-galactosyl-O-β-D-xylosylprotein 3-β-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:[protein]-3-O-(β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine (configuration-inverting)
Comments: Involved in the biosynthesis of the linkage region of glycosaminoglycan chains as part of proteoglycan biosynthesis (chondroitin, dermatan and heparan sulfates). Requires Mn2+.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 56626-21-2, 56626-19-8
References:
1.  Robinson, J.A. and Robinson, H.C. Initiation of chondroitin sulphate synthesis by β-D-galactosides. Substrates for galactosyltransferase II. Biochem. J. 227 (1985) 805–814. [PMID: 3924029]
2.  Schwartz, N.B. and Roden, L. Biosynthesis of chondroitin sulfate. Solubilization of chondroitin sulfate glycosyltransferases and partial purification of uridine diphosphate-D-galactose:D-xylose galactosyltransferase. J. Biol. Chem. 250 (1975) 5200–5207. [PMID: 1150655]
3.  Bai, X., Zhou, D., Brown, J.R., Crawford, B.E., Hennet, T. and Esko, J.D. Biosynthesis of the linkage region of glycosaminoglycans: cloning and activity of galactosyltransferase II, the sixth member of the β1,3-galactosyltransferase family (β3GalT6). J. Biol. Chem. 276 (2001) 48189–48195. [DOI] [PMID: 11551958]
[EC 2.4.1.134 created 1984, modified 2002]
 
 
EC 2.7.1.227     Relevance: 52%
Accepted name: inositol phosphorylceramide synthase
Reaction: 1-phosphatidyl-1D-myo-inositol + a very-long-chain (2′R)-2′-hydroxy-phytoceramide = 1,2-diacyl-sn-glycerol + a (4R)-4-hydroxy-N-[(2R)-2-hydroxy-very-long-chain-acyl]-1-O-[(1D-myo-inositol-1-O-yl)hydroxyphosphoryl]sphinganine
Glossary: a (4R)-4-hydroxy-N-[(2R)-2-hydroxy-very-long-chain-acyl]-1-O-[(1D-myo-inositol-1-O-yl)hydroxyphosphoryl]sphinganine = a very-long-chain inositol phospho-α hydroxyphytoceramide = IPC
Other name(s): AUR1 (gene name); KEI1 (gene name)
Systematic name: 1-phosphatidyl-1D-myo-inositol:a very-long-chain (2′R)-2′-hydroxy-phytoceramide phosphoinositoltransferase
Comments: The enzyme, characterized from yeast, attaches a phosphoinositol headgroup to α-hydroxyphytoceramides, generating a very-long-chain inositol phospho-α hydroxyphytoceramide (IPC), the simplest of the three complex sphingolipids produced by yeast.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Nagiec, M.M., Nagiec, E.E., Baltisberger, J.A., Wells, G.B., Lester, R.L. and Dickson, R.C. Sphingolipid synthesis as a target for antifungal drugs. Complementation of the inositol phosphorylceramide synthase defect in a mutant strain of Saccharomyces cerevisiae by the AUR1 gene. J. Biol. Chem. 272 (1997) 9809–9817. [PMID: 9092515]
2.  Levine, T.P., Wiggins, C.A. and Munro, S. Inositol phosphorylceramide synthase is located in the Golgi apparatus of Saccharomyces cerevisiae. Mol. Biol. Cell 11 (2000) 2267–2281. [PMID: 10888667]
3.  Sato, K., Noda, Y. and Yoda, K. Kei1: a novel subunit of inositolphosphorylceramide synthase, essential for its enzyme activity and Golgi localization. Mol. Biol. Cell 20 (2009) 4444–4457. [PMID: 19726565]
[EC 2.7.1.227 created 2019]
 
 


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