The Enzyme Database

Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)

Proposed Changes to the Enzyme List

The entries below are proposed additions and amendments to the Enzyme Nomenclature list. They were prepared for the NC-IUBMB by Kristian Axelsen, Ron Caspi, Ture Damhus, Shinya Fushinobu, Julia Hauenstein, Antje Jäde, Ingrid Keseler, Masaaki Kotera, Andrew McDonald, Gerry Moss, Ida Schomburg and Keith Tipton. Comments and suggestions on these draft entries should be sent to Dr Andrew McDonald (Department of Biochemistry, Trinity College Dublin, Dublin 2, Ireland). The date on which an enzyme will be made official is appended after the EC number. To prevent confusion please do not quote new EC numbers until they are incorporated into the main list.

An asterisk before 'EC' indicates that this is an amendment to an existing enzyme rather than a new enzyme entry.


Contents

EC 1.1.1.294 chlorophyll(ide) b reductase
EC 1.1.99.32 L-sorbose 1-dehydrogenase
EC 1.3.1.80 red chlorophyll catabolite reductase
*EC 1.5.1.12 1-pyrroline-5-carboxylate dehydrogenase
EC 1.14.12.20 pheophorbide a oxygenase
*EC 2.1.1.70 8-hydroxyfuranocoumarin 8-O-methyltransferase
EC 2.1.1.93 deleted
EC 2.1.1.162 glycine/sarcosine/dimethylglycine N-methyltransferase
EC 2.7.7.65 diguanylate cyclase
*EC 3.1.1.14 chlorophyllase
EC 3.1.1.82 pheophorbidase
EC 3.1.4.52 cyclic-guanylate-specific phosphodiesterase
EC 3.4.22.66 calicivirin
EC 3.4.22.68 Ulp1 peptidase
*EC 3.5.1.54 allophanate hydrolase
*EC 3.5.1.84 biuret amidohydrolase
EC 3.5.1.98 histone deacetylase
*EC 3.5.2.15 cyanuric acid amidohydrolase
*EC 4.3.1.3 histidine ammonia-lyase
EC 4.3.1.5 transferred
EC 4.3.1.11 deleted
EC 4.3.1.22 3,4-dihydroxyphenylalanine reductive deaminase
EC 4.3.1.23 tyrosine ammonia-lyase
EC 4.3.1.24 phenylalanine ammonia-lyase
EC 4.3.1.25 phenylalanine/tyrosine ammonia-lyase
EC 5.1.3.23 UDP-2,3-diacetamido-2,3-dideoxyglucuronic acid 2-epimerase


EC 1.1.1.294
Accepted name: chlorophyll(ide) b reductase
Reaction: 71-hydroxychlorophyllide a + NAD(P)+ = chlorophyllide b + NAD(P)H + H+
For diagram of the chlorophyll cycle, click here
Other name(s): chlorophyll b reductase; Chl b reductase
Systematic name: 71-hydroxychlorophyllide-a:NAD(P)+ oxidoreductase
Comments: This enzyme carries out the first step in the conversion of chlorophyll b to chlorophyll a. It is involved in chlorophyll degradation, which occurs during leaf senescence [3] and it also forms part of the chlorophyll cycle, which interconverts chlorophyll a and b in response to changing light conditions [4,5].
Links to other databases: BRENDA, EXPASY, Gene, KEGG
References:
1.  Scheumann, V., Ito, H., Tanaka, A., Schoch, S. and Rüdiger, W. Substrate specificity of chlorophyll(ide) b reductase in etioplasts of barley (Hordeum vulgare L.). Eur. J. Biochem. 242 (1996) 163–170. [DOI] [PMID: 8954166]
2.  Scheumann, V., Schoch, S. and Rüdiger, W. Chlorophyll a formation in the chlorophyll b reductase reaction requires reduced ferredoxin. J. Biol. Chem. 273 (1998) 35102–35108. [DOI] [PMID: 9857045]
3.  Hörtensteiner, S. Chlorophyll degradation during senescence. Annu. Rev. Plant Biol. 57 (2006) 55–77. [DOI] [PMID: 16669755]
4.  Ito, H., Ohtsuka, T. and Tanaka, A. Conversion of chlorophyll b to chlorophyll a via 7-hydroxymethyl chlorophyll. J. Biol. Chem. 271 (1996) 1475–1479. [DOI] [PMID: 8576141]
5.  Rüdiger, W. Biosynthesis of chlorophyll b and the chlorophyll cycle. Photosynth. Res. 74 (2002) 187–193. [DOI] [PMID: 16228557]
[EC 1.1.1.294 created 2007]
 
 
EC 1.1.99.32
Accepted name: L-sorbose 1-dehydrogenase
Reaction: L-sorbose + acceptor = 1-dehydro-L-sorbose + reduced acceptor
Glossary: 1-dehydro-L-sorbose = L-sorbosone = 2-dehydro-L-gulose
Other name(s): SDH (ambiguous)
Systematic name: L-sorbose:acceptor 1-oxidoreductase
Comments: The product, L-sorbosone, is an intermediate in bacterial 2-keto-L-gulonic-acid formation. The activity of this membrane-bound enzyme is stimulated by Fe(III) or Co2+ but is inhibited by Cu2+. The enzyme is highly specific for L-sorbose as other sugars, such as glucose, mannitol and sorbitol, are not substrates. Phenazine methosulfate and DCIP can act as artificial acceptors.
Links to other databases: BRENDA, EXPASY, Gene, KEGG
References:
1.  Sugisawa, T., Hoshino, T., Nomura, S. and Fujiwara, A. Isolation and characterization of membrane-bound L-sorbose dehydrogenase from Gluconobacter melanogenus UV10. Agric. Biol. Chem. 55 (1991) 363–370.
[EC 1.1.99.32 created 2008]
 
 
EC 1.3.1.80
Transferred entry: red chlorophyll catabolite reductase. Now classified as EC 1.3.7.12, red chlorophyll catabolite reductase
[EC 1.3.1.80 created 2007, deleted 2016]
 
 
*EC 1.5.1.12
Transferred entry: 1-pyrroline-5-carboxylate dehydrogenase. Now EC 1.2.1.88, L-glutamate γ-semialdehyde dehydrogenase.
[EC 1.5.1.12 created 1972, modified 2008, deleted 2013]
 
 
EC 1.14.12.20
Transferred entry: pheophorbide a oxygenase. Now classified as EC 1.14.15.17, pheophorbide a oxygenase.
[EC 1.14.12.20 created 2007, deleted 2016]
 
 
*EC 2.1.1.70
Accepted name: 8-hydroxyfuranocoumarin 8-O-methyltransferase
Reaction: (1) S-adenosyl-L-methionine + an 8-hydroxyfurocoumarin = S-adenosyl-L-homocysteine + an 8-methoxyfurocoumarin (general reaction)
(2) S-adenosyl-L-methionine + xanthotoxol = S-adenosyl-L-homocysteine + xanthotoxin
For diagram of reaction, click here
Glossary: xanthotoxin = O-methylxanthotoxol = 8-methoxypsoralen
xanthotoxol = 8-hydroxypsoralen
Other name(s): furanocoumarin 8-methyltransferase; furanocoumarin 8-O-methyl-transferase; xanthotoxol 8-O-methyltransferase; XMT; 8-hydroxyfuranocoumarin 8-O-methyltransferase; SAM:xanthotoxol O-methyltransferase; S-adenosyl-L-methionine:8-hydroxyfuranocoumarin 8-O-methyltransferase; xanthotoxol methyltransferase; xanthotoxol O-methyltransferase; S-adenosyl-L-methionine:xanthotoxol O-methyltransferase; S-adenosyl-L-methionine-xanthotoxol O-methyltransferase
Systematic name: S-adenosyl-L-methionine:8-hydroxyfurocoumarin 8-O-methyltransferase
Comments: Converts xanthotoxol into xanthotoxin, which has therapeutic potential in the treatment of psoriasis as it has photosensitizing and antiproliferative activities [4]. Methylates the 8-hydroxy group of some hydroxy- and methylcoumarins, but has little activity on non-coumarin phenols (see also EC 2.1.1.69, 5-hydroxyfuranocoumarin 5-O-methyltransferase).
Links to other databases: BRENDA, EXPASY, KEGG, PDB, CAS registry number: 67339-13-3
References:
1.  Thompson, H.J., Sharma, S.K. and Brown, S.A. O-Methyltransferases of furanocoumarin biosynthesis. Arch. Biochem. Biophys. 188 (1978) 272–281. [DOI] [PMID: 28084]
2.  Hauffe, K.D., Hahlbrock, K. and Scheel, D. Elicitor-stimulated furanocoumarin biosynthesis in cultured parsley cells - S-adenosyl-L-methionine-bergaptol and S-adenosyl-L-methionine-xanthotoxol O-methyltransferases. Z. Naturforsch. C: Biosci. 41 (1986) 228–239.
3.  Sharma, S.K., Garrett, J.M. and Brown, S.A. Separation of the S-adenosylmethionine: 5- and 8-hydroxyfuranocoumarin O-methyltransferases of Ruta graveolens L. by general ligand affinity chromatography. Z. Naturforsch. [C] 34C (1979) 387–391. [PMID: 156999]
4.  Hehmann, M., Lukačin, R., Ekiert, H. and Matern, U. Furanocoumarin biosynthesis in Ammi majus L. Cloning of bergaptol O-methyltransferase. Eur. J. Biochem. 271 (2004) 932–940. [PMID: 15009205]
[EC 2.1.1.70 created 1984, modified 2006 (EC 2.1.1.93 created 2006, incorporated 2008)]
 
 
EC 2.1.1.93
Deleted entry: xanthotoxol O-methyltransferase. Enzyme is identical to EC 2.1.1.70, 8-hydroxyfuranocoumarin 8-O-methyltransferase
[EC 2.1.1.93 created 1989, deleted 2008]
 
 
EC 2.1.1.162
Accepted name: glycine/sarcosine/dimethylglycine N-methyltransferase
Reaction: 3 S-adenosyl-L-methionine + glycine = 3 S-adenosyl-L-homocysteine + betaine (overall reaction)
(1a) S-adenosyl-L-methionine + glycine = S-adenosyl-L-homocysteine + sarcosine
(1b) S-adenosyl-L-methionine + sarcosine = S-adenosyl-L-homocysteine + N,N-dimethylglycine
(1c) S-adenosyl-L-methionine + N,N-dimethylglycine = S-adenosyl-L-homocysteine + betaine
Glossary: sarcosine = N-methylglycine
betaine = glycine betaine = N,N,N-trimethylglycine = N,N,N-trimethylammonioacetate
Other name(s): GSDMT; glycine sarcosine dimethylglycine N-methyltransferase
Systematic name: S-adenosyl-L-methionine:glycine(or sarcosine or N,N-dimethylglycine) N-methyltransferase [sarcosine(or N,N-dimethylglycine or betaine)-forming]
Comments: Unlike EC 2.1.1.156 (glycine/sarcosine N-methyltransferase), EC 2.1.1.157 (sarcosine/dimethylglycine N-methyltransferase) and EC 2.1.1.161 (dimethylglycine N-methyltransferase), this enzyme, from the halophilic methanoarchaeon Methanohalophilus portucalensis, can methylate glycine and all of its intermediates to form the compatible solute betaine [1].
Links to other databases: BRENDA, EXPASY, KEGG
References:
1.  Lai, M.C., Wang, C.C., Chuang, M.J., Wu, Y.C. and Lee, Y.C. Effects of substrate and potassium on the betaine-synthesizing enzyme glycine sarcosine dimethylglycine N-methyltransferase from a halophilic methanoarchaeon Methanohalophilus portucalensis. Res. Microbiol. 157 (2006) 948–955. [DOI] [PMID: 17098399]
[EC 2.1.1.162 created 2007]
 
 
EC 2.7.7.65
Accepted name: diguanylate cyclase
Reaction: 2 GTP = 2 diphosphate + cyclic di-3′,5′-guanylate
For diagram of cyclic di-3′,5′-guanylate biosynthesis and breakdown, click here
Glossary: cyclic di-3′,5′-guanylate = c-di-GMP = c-di-guanylate = cyclic-bis(3′→5′) dimeric GMP
Other name(s): DGC; PleD
Systematic name: GTP:GTP guanylyltransferase (cyclizing)
Comments: A GGDEF-domain-containing protein that requires Mg2+ or Mn2+ for activity. The enzyme can be activated by BeF3, a phosphoryl mimic, which results in dimerization [3]. Dimerization is required but is not sufficient for diguanylate-cyclase activity [3]. Cyclic di-3′,5′-guanylate is an intracellular signalling molecule that controls motility and adhesion in bacterial cells. It was first identified as having a positive allosteric effect on EC 2.4.1.12, cellulose synthase (UDP-forming) [1].
Links to other databases: BRENDA, EXPASY, Gene, KEGG, PDB, CAS registry number: 146316-82-7
References:
1.  Ryjenkov, D.A., Tarutina, M., Moskvin, O.V. and Gomelsky, M. Cyclic diguanylate is a ubiquitous signaling molecule in bacteria: insights into biochemistry of the GGDEF protein domain. J. Bacteriol. 187 (2005) 1792–1798. [DOI] [PMID: 15716451]
2.  Méndez-Ortiz, M.M., Hyodo, M., Hayakawa, Y. and Membrillo-Hernández, J. Genome-wide transcriptional profile of Escherichia coli in response to high levels of the second messenger 3′,5′-cyclic diguanylic acid. J. Biol. Chem. 281 (2006) 8090–8099. [DOI] [PMID: 16418169]
3.  Paul, R., Abel, S., Wassmann, P., Beck, A., Heerklotz, H. and Jenal, U. Activation of the diguanylate cyclase PleD by phosphorylation-mediated dimerization. J. Biol. Chem. 282 (2007) 29170–29177. [DOI] [PMID: 17640875]
[EC 2.7.7.65 created 2008]
 
 
*EC 3.1.1.14
Accepted name: chlorophyllase
Reaction: chlorophyll + H2O = phytol + chlorophyllide
For diagram of chlorophyll catabolism, click here
Other name(s): CLH; Chlase
Systematic name: chlorophyll chlorophyllidohydrolase
Comments: Chlorophyllase has been found in higher plants, diatoms, and in the green algae Chlorella [3]. This enzyme forms part of the chlorophyll degradation pathway and is thought to take part in de-greening processes such as fruit ripening, leaf senescence and flowering, as well as in the turnover and homeostasis of chlorophyll [4]. This enzyme acts preferentially on chlorophyll a but will also accept chlorophyll b and pheophytins as substrates [5]. Ethylene and methyl jasmonate, which are known to accelerate senescence in many species, can enhance the activity of the hormone-inducible form of this enzyme [5].
Links to other databases: BRENDA, EXPASY, Gene, KEGG, PDB, CAS registry number: 9025-96-1
References:
1.  Holden, M. The breakdown of chlorophyll by chlorophyllase. Biochem. J. 78 (1961) 359–364. [PMID: 13715233]
2.  Klein, A.O. and Vishniac, W. Activity and partial purification of chlorophyllase in aqueous systems. J. Biol. Chem. 236 (1961) 2544–2547. [PMID: 13756631]
3.  Tsuchiya, T., Ohta, H., Okawa, K., Iwamatsu, A., Shimada, H., Masuda, T. and Takamiya, K. Cloning of chlorophyllase, the key enzyme in chlorophyll degradation: finding of a lipase motif and the induction by methyl jasmonate. Proc. Natl. Acad. Sci. USA 96 (1999) 15362–15367. [DOI] [PMID: 10611389]
4.  Okazawa, A., Tango, L., Itoh, Y., Fukusaki, E. and Kobayashi, A. Characterization and subcellular localization of chlorophyllase from Ginkgo biloba. Z. Naturforsch. [C] 61 (2006) 111–117. [PMID: 16610227]
5.  Hörtensteiner, S. Chlorophyll degradation during senescence. Annu. Rev. Plant Biol. 57 (2006) 55–77. [DOI] [PMID: 16669755]
[EC 3.1.1.14 created 1961, modified 2007]
 
 
EC 3.1.1.82
Accepted name: pheophorbidase
Reaction: pheophorbide a + H2O = pyropheophorbide a + methanol + CO2 (overall reaction)
(1a) pheophorbide a + H2O = C-132-carboxypyropheophorbide a + methanol
(1b) C-132-carboxypyropheophorbide a = pyropheophorbide a + CO2 (spontaneous)
For diagram of chlorophyll catabolism, click here
Other name(s): phedase; PPD
Systematic name: pheophorbide-a hydrolase
Comments: This enzyme forms part of the chlorophyll degradation pathway, and is found in higher plants and in algae. In higher plants it participates in de-greening processes such as fruit ripening, leaf senescence, and flowering. The enzyme exists in two forms: type 1 is induced by senescence whereas type 2 is constitutively expressed [1,2]. The enzyme is highly specific for pheophorbide as substrate (with a preference for pheophorbide a over pheophorbide b) as other chlorophyll derivatives such as protochlorophyllide a, pheophytin a and c, chlorophyll a and b, and chlorophyllide a cannot act as substrates [2]. Another enzyme, called pheophorbide demethoxycarbonylase (PDC), produces pyropheophorbide a from pheophorbide a without forming an intermediate although the precise reaction is not yet known [1].
Links to other databases: BRENDA, EXPASY, KEGG, PDB
References:
1.  Suzuki, Y., Doi, M. and Shioi, Y. Two enzymatic reaction pathways in the formation of pyropheophorbide a. Photosynth. Res. 74 (2002) 225–233. [DOI] [PMID: 16228561]
2.  Suzuki, Y., Amano, T. and Shioi, Y. Characterization and cloning of the chlorophyll-degrading enzyme pheophorbidase from cotyledons of radish. Plant Physiol. 140 (2006) 716–725. [DOI] [PMID: 16384908]
3.  Hörtensteiner, S. Chlorophyll degradation during senescence. Annu. Rev. Plant Biol. 57 (2006) 55–77. [DOI] [PMID: 16669755]
[EC 3.1.1.82 created 2007]
 
 
EC 3.1.4.52
Accepted name: cyclic-guanylate-specific phosphodiesterase
Reaction: cyclic di-3′,5′-guanylate + H2O = 5′-phosphoguanylyl(3′→5′)guanosine
For diagram of cyclic di-3′,5′-guanylate biosynthesis and breakdown, click here
Glossary: c-di-GMP = c-di-guanylate = cyclic di-3′,5′-guanylate = cyclic-bis(3′→5′) dimeric GMP
Other name(s): cyclic bis(3′→5′)diguanylate phosphodiesterase; c-di-GMP-specific phosphodiesterase; c-di-GMP phosphodiesterase; phosphodiesterase (misleading); phosphodiesterase A1; PDEA1; VieA
Systematic name: cyclic bis(3′→5′)diguanylate 3′-guanylylhydrolase
Comments: Requires Mg2+ or Mn2+ for activity and is inhibited by Ca2+ and Zn2+. Contains a heme unit. This enzyme linearizes cyclic di-3′,5′-guanylate, the product of EC 2.7.7.65, diguanylate cyclase and an allosteric activator of EC 2.4.1.12, cellulose synthase (UDP-forming), rendering it inactive [1]. It is the balance between these two enzymes that determines the cellular level of c-di-GMP [1].
Links to other databases: BRENDA, EXPASY, Gene, KEGG, PDB, CAS registry number: 338732-46-0
References:
1.  Chang, A.L., Tuckerman, J.R., Gonzalez, G., Mayer, R., Weinhouse, H., Volman, G., Amikam, D., Benziman, M. and Gilles-Gonzalez, M.A. Phosphodiesterase A1, a regulator of cellulose synthesis in Acetobacter xylinum, is a heme-based sensor. Biochemistry 40 (2001) 3420–3426. [DOI] [PMID: 11297407]
2.  Christen, M., Christen, B., Folcher, M., Schauerte, A. and Jenal, U. Identification and characterization of a cyclic di-GMP-specific phosphodiesterase and its allosteric control by GTP. J. Biol. Chem. 280 (2005) 30829–30837. [DOI] [PMID: 15994307]
3.  Schmidt, A.J., Ryjenkov, D.A. and Gomelsky, M. The ubiquitous protein domain EAL is a cyclic diguanylate-specific phosphodiesterase: enzymatically active and inactive EAL domains. J. Bacteriol. 187 (2005) 4774–4781. [DOI] [PMID: 15995192]
4.  Tamayo, R., Tischler, A.D. and Camilli, A. The EAL domain protein VieA is a cyclic diguanylate phosphodiesterase. J. Biol. Chem. 280 (2005) 33324–33330. [DOI] [PMID: 16081414]
[EC 3.1.4.52 created 2008]
 
 
EC 3.4.22.66
Accepted name: calicivirin
Reaction: Endopeptidase with a preference for cleavage when the P1 position is occupied by Glu┼ and the P1′ position is occupied by Gly┼
Other name(s): Camberwell virus processing peptidase; Chiba virus processing peptidase; Norwalk virus processing peptidase; Southampton virus processing peptidase; Southampton virus; norovirus virus processing peptidase; calicivirus trypsin-like cysteine protease; calicivirus TCP; calicivirus 3C-like protease; calicivirus endopeptidase; rabbit hemorrhagic disease virus 3C endopeptidase
Comments: Viruses that are members of the Norovirus genus (Caliciviridae family) are a major cause of epidemic acute viral gastroenteritis [4]. The nonstructural proteins of these viruses are produced by proteolytic cleavage of a large precursor polyprotein, performed by a protease that is incorporated into the polyprotein [6]. Cleavage sites are apparently defined by features based on both sequence and structure since several sites in the polyprotein fulfilling the identified sequence requirements are not cleaved [1]. The presence of acidic (Asp), basic (Arg), aromatic (Tyr) or aliphatic (Leu) amino acids at the P1′ position results in only minor differences in cleavage efficiency, suggesting that steric or conformational constraints may play a role in determining specificity [1]. Changes to the amino acid at the P2 position do not alter cleavage efficiency [1,2]. Belongs in peptidase family C37.
Links to other databases: BRENDA, EXPASY, Gene, KEGG, MEROPS, PDB
References:
1.  Meyers, G., Rossi, C. and Thiel, H.J. Calicivirus endopeptidases. In: Barrett, A.J., Rawlings, N.D. and Woessner, J.F. (Ed.), Handbook of Proteolytic Enzymes, 2nd edn, Elsevier, London, 2004, pp. 1380–1382.
2.  Wirblich, C., Sibilia, M., Boniotti, M.B., Rossi, C., Thiel, H.J. and Meyers, G. 3C-like protease of rabbit hemorrhagic disease virus: identification of cleavage sites in the ORF1 polyprotein and analysis of cleavage specificity. J. Virol. 69 (1995) 7159–7168. [PMID: 7474137]
3.  Martín Alonso, J.M., Casais, R., Boga, J.A. and Parra, F. Processing of rabbit hemorrhagic disease virus polyprotein. J. Virol. 70 (1996) 1261–1265. [PMID: 8551592]
4.  Liu, B., Clarke, I.N. and Lambden, P.R. Polyprotein processing in Southampton virus: identification of 3C-like protease cleavage sites by in vitro mutagenesis. J. Virol. 70 (1996) 2605–2610. [PMID: 8642693]
5.  Liu, B.L., Viljoen, G.J., Clarke, I.N. and Lambden, P.R. Identification of further proteolytic cleavage sites in the Southampton calicivirus polyprotein by expression of the viral protease in E. coli. J. Gen. Virol. 80 (1999) 291–296. [DOI] [PMID: 10073687]
[EC 3.4.22.66 created 2007]
 
 
EC 3.4.22.68
Accepted name: Ulp1 peptidase
Reaction: Hydrolysis of the α-linked peptide bond in the sequence Gly-Gly┼Ala-Thr-Tyr at the C-terminal end of the small ubiquitin-like modifier (SUMO) propeptide, Smt3, leading to the mature form of the protein. A second reaction involves the cleavage of an ε-linked peptide bond between the C-terminal glycine of the mature SUMO and the lysine ε-amino group of the target protein
Other name(s): Smt3-protein conjugate proteinase; Ubl-specific protease 1; Ulp1; Ulp1 endopeptidase; Ulp1 protease
Comments: The enzyme from Saccharomyces cerevisiae can also recognize small ubiquitin-like modifier 1 (SUMO-1) from human as a substrate in both SUMO-processing (α-linked peptide bonds) and SUMO-deconjugation (ε-linked peptide bonds) reactions [1,2,3]. Ulp1 has several functions, including an essential role in chromosomal segregation and progression of the cell cycle through the G2/M phase of the cell cycle. Belongs in peptidase family C48.
Links to other databases: BRENDA, EXPASY, Gene, KEGG, PDB
References:
1.  Lima, C.D. Ulp1 endopeptidase. In: Barrett, A.J., Rawlings, N.D. and Woessner, J.F. (Ed.), Handbook of Proteolytic Enzymes, 2nd edn, Elsevier, London, 2004, pp. 1340–1344.
2.  Li, S.-J. and Hochstrasser, M. A new protease required for cell-cycle progression in yeast. Nature 398 (1999) 246–251. [DOI] [PMID: 10094048]
3.  Taylor, D.L., Ho, J.C., Oliver, A. and Watts, F.Z. Cell-cycle-dependent localisation of Ulp1, a Schizosaccharomyces pombe Pmt3 (SUMO)-specific protease. J. Cell Sci. 115 (2002) 1113–1122. [PMID: 11884512]
4.  Li, S.-J. and Hochstrasser, M. The Ulp1 SUMO isopeptidase: distinct domains required for viability, nuclear envelope localization, and substrate specificity. J. Cell Biol. 160 (2003) 1069–1081. [DOI] [PMID: 12654900]
5.  Ihara, M., Koyama, H., Uchimura, Y., Saitoh, H. and Kikuchi, A. Noncovalent binding of small ubiquitin-related modifier (SUMO) protease to SUMO is necessary for enzymatic activities and cell growth. J. Biol. Chem. 282 (2007) 16465–16475. [DOI] [PMID: 17428805]
6.  Mukhopadhyay, D. and Dasso, M. Modification in reverse: the SUMO proteases. Trends Biochem. Sci. 32 (2007) 286–295. [DOI] [PMID: 17499995]
[EC 3.4.22.68 created 2008, modified 2011]
 
 
*EC 3.5.1.54
Accepted name: allophanate hydrolase
Reaction: urea-1-carboxylate + H2O = 2 CO2 + 2 NH3
For diagram of atrazine catabolism, click here
Glossary: allophanate = urea-1-carboxylate
Other name(s): allophanate lyase; AtzF; TrzF
Systematic name: urea-1-carboxylate amidohydrolase
Comments: Along with EC 3.5.2.15 (cyanuric acid amidohydrolase) and EC 3.5.1.84 (biuret amidohydrolase), this enzyme forms part of the cyanuric-acid metabolism pathway, which degrades s-triazide herbicides, such as atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-1,3,5-triazine], in bacteria. The yeast enzyme (but not that from green algae) also catalyses the reaction of EC 6.3.4.6, urea carboxylase, thus bringing about the hydrolysis of urea to CO2 and NH3 in the presence of ATP and bicarbonate. The enzyme from Pseudomonas sp. strain ADP has a narrow substrate specificity, being unable to use the structurally analogous compounds urea, hydroxyurea or methylcarbamate as substrate [6].
Links to other databases: BRENDA, EAWAG-BBD, EXPASY, Gene, KEGG, PDB, CAS registry number: 9076-72-6
References:
1.  Maitz, G.S., Haas, E.M. and Castric, P.A. Purification and properties of the allophanate hydrolase from Chlamydomonas reinhardii. Biochim. Biophys. Acta 714 (1982) 486–491.
2.  Roon, R.J. and Levenberg, B. Urea amidolyase. I. Properties of the enzyme from Candida utilis. J. Biol. Chem. 247 (1972) 4107–4113. [PMID: 4556303]
3.  Sumrada, R.A. and Cooper, T.G. Urea carboxylase and allophanate hydrolase are components of a multifunctional protein in yeast. J. Biol. Chem. 257 (1982) 9119–9127. [PMID: 6124544]
4.  Kanamori, T., Kanou, N., Kusakabe, S., Atomi, H. and Imanaka, T. Allophanate hydrolase of Oleomonas sagaranensis involved in an ATP-dependent degradation pathway specific to urea. FEMS Microbiol. Lett. 245 (2005) 61–65. [DOI] [PMID: 15796980]
5.  Cheng, G., Shapir, N., Sadowsky, M.J. and Wackett, L.P. Allophanate hydrolase, not urease, functions in bacterial cyanuric acid metabolism. Appl. Environ. Microbiol. 71 (2005) 4437–4445. [DOI] [PMID: 16085834]
6.  Shapir, N., Sadowsky, M.J. and Wackett, L.P. Purification and characterization of allophanate hydrolase (AtzF) from Pseudomonas sp. strain ADP. J. Bacteriol. 187 (2005) 3731–3738. [DOI] [PMID: 15901697]
7.  Shapir, N., Cheng, G., Sadowsky, M.J. and Wackett, L.P. Purification and characterization of TrzF: biuret hydrolysis by allophanate hydrolase supports growth. Appl. Environ. Microbiol. 72 (2006) 2491–2495. [DOI] [PMID: 16597948]
[EC 3.5.1.54 created 1986, modified 2008]
 
 
*EC 3.5.1.84
Accepted name: biuret amidohydrolase
Reaction: biuret + H2O = urea-1-carboxylate + NH3
For diagram of atrazine catabolism, click here
Glossary: biuret = imidodicarbonic diamide
allophanate = urea-1-carboxylate
Other name(s): biuH (gene name)
Systematic name: biuret amidohydrolase
Comments: The enzyme, characterized from the bacterium Rhizobium leguminosarum bv. viciae 3841, participates in the degradation of cyanuric acid, an intermediate in the degradation of s-triazide herbicides such as atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-1,3,5-triazine]. The substrate, biuret, forms by the spontaneous decarboxylation of 1-carboxybiuret in the absence of EC 3.5.1.131, 1-carboxybiuret hydrolase.
Links to other databases: BRENDA, EAWAG-BBD, EXPASY, Gene, KEGG, PDB, CAS registry number: 95567-88-7
References:
1.  Cameron, S.M., Durchschein, K., Richman, J.E., Sadowsky, M.J. and Wackett, L.P. A new family of biuret hydrolases involved in s-triazine ring metabolism. ACS Catal. 2011 (2011) 1075–1082. [PMID: 21897878]
2.  Esquirol, L., Peat, T.S., Wilding, M., Lucent, D., French, N.G., Hartley, C.J., Newman, J. and Scott, C. Structural and biochemical characterization of the biuret hydrolase (BiuH) from the cyanuric acid catabolism pathway of Rhizobium leguminosarum bv. viciae 3841. PLoS One 13:e0192736 (2018). [PMID: 29425231]
3.  Esquirol, L., Peat, T.S., Wilding, M., Liu, J.W., French, N.G., Hartley, C.J., Onagi, H., Nebl, T., Easton, C.J., Newman, J. and Scott, C. An unexpected vestigial protein complex reveals the evolutionary origins of an s-triazine catabolic enzyme. J. Biol. Chem. 293 (2018) 7880–7891. [DOI] [PMID: 29523689]
[EC 3.5.1.84 created 2000, modified 2008, modified 2019]
 
 
EC 3.5.1.98
Accepted name: histone deacetylase
Reaction: Hydrolysis of an N6-acetyl-lysine residue of a histone to yield a deacetylated histone
Other name(s): HDAC
Systematic name: histone amidohydrolase
Comments: A class of enzymes that remove acetyl groups from N6-acetyl-lysine residues on a histone. The reaction of this enzyme is opposite to that of EC 2.3.1.48, histone acetyltransferase. Histone deacetylases (HDACs) can be organized into three classes, HDAC1, HDAC2 and HDAC3, depending on sequence similarity and domain organization. Histone acetylation plays an important role in regulation of gene expression. In eukaryotes, HDACs play a key role in the regulation of transcription and cell proliferation [4]. May be identical to EC 3.5.1.17, acyl-lysine deacylase.
Links to other databases: BRENDA, EXPASY, Gene, KEGG, PDB
References:
1.  Krieger, D.E., Levine, R., Merrifield, R.B., Vidali, G. and Allfrey, V.G. Chemical studies of histone acetylation. Substrate specificity of a histone deacetylase from calf thymus nuclei. J. Biol. Chem. 249 (1974) 332–334. [PMID: 4855628]
2.  Sanchez del Pino, M.M., Lopez-Rodas, G., Sendra, R. and Tordera, V. Properties of the yeast nuclear histone deacetylase. Biochem. J. 303 (1994) 723–729. [PMID: 7980438]
3.  Ouaissi, M. and Ouaissi, A. Histone deacetylase enzymes as potential drug targets in cancer and parasitic diseases. J. Biomed. Biotechnol. 2006 (2006) 13474. [DOI] [PMID: 16883049]
4.  Song, Y.M., Kim, Y.S., Kim, D., Lee, D.S. and Kwon, H.J. Cloning, expression, and biochemical characterization of a new histone deacetylase-like protein from Thermus caldophilus GK24. Biochem. Biophys. Res. Commun. 361 (2007) 55–61. [DOI] [PMID: 17632079]
5.  Finnin, M.S., Donigian, J.R., Cohen, A., Richon, V.M., Rifkind, R.A., Marks, P.A., Breslow, R. and Pavletich, N.P. Structures of a histone deacetylase homologue bound to the TSA and SAHA inhibitors. Nature 401 (1999) 188–193. [DOI] [PMID: 10490031]
6.  Phiel, C.J., Zhang, F., Huang, E.Y., Guenther, M.G., Lazar, M.A. and Klein, P.S. Histone deacetylase is a direct target of valproic acid, a potent anticonvulsant, mood stabilizer, and teratogen. J. Biol. Chem. 276 (2001) 36734–36741. [DOI] [PMID: 11473107]
7.  de Ruijter, A.J., van Gennip, A.H., Caron, H.N., Kemp, S. and van Kuilenburg, A.B. Histone deacetylases (HDACs): characterization of the classical HDAC family. Biochem. J. 370 (2003) 737–749. [DOI] [PMID: 12429021]
[EC 3.5.1.98 created 2008]
 
 
*EC 3.5.2.15
Accepted name: cyanuric acid amidohydrolase
Reaction: cyanuric acid + H2O = 1-carboxybiuret
For diagram of atrazine catabolism, click here
Glossary: cyanuric acid = 1,3,5-triazine-2,4,6(1H,3H,5H)-trione = 2,4,6-trihydroxy-s-triazine
1-carboxybiuret = N-[(carbamoylamino)carbonyl]carbamate
Other name(s): atzD (gene name); trzD (gene name)
Systematic name: cyanuric acid amidohydrolase
Comments: The enzyme catalyses the ring cleavage of cyanuric acid, an intermediate in the degradation of s-triazide herbicides such as atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-1,3,5-triazine]. The enzyme is highly specific for cyanuric acid. The product was initially thought to be biuret, but was later shown to be 1-carboxybiuret.
Links to other databases: BRENDA, EAWAG-BBD, EXPASY, Gene, KEGG, PDB, CAS registry number: 132965-78-7
References:
1.  Eaton, R.W. and Karns, J.S. Cloning and comparison of the DNA encoding ammelide aminohydrolase and cyanuric acid amidohydrolase from three s-triazine-degrading bacterial strains. J. Bacteriol. 173 (1991) 1363–1366. [DOI] [PMID: 1991731]
2.  Eaton, R.W. and Karns, J.S. Cloning and analysis of s-triazine catabolic genes from Pseudomonas sp. strain NRRLB-12227. J. Bacteriol. 173 (1991) 1215–1222. [DOI] [PMID: 1846859]
3.  Karns, J.S. Gene sequence and properties of an s-triazine ring-cleavage enzyme from Pseudomonas sp. strain NRRLB-12227. Appl. Environ. Microbiol. 65 (1999) 3512–3517. [DOI] [PMID: 10427042]
4.  Fruchey, I., Shapir, N., Sadowsky, M.J. and Wackett, L.P. On the origins of cyanuric acid hydrolase: purification, substrates, and prevalence of AtzD from Pseudomonas sp. strain ADP. Appl. Environ. Microbiol. 69 (2003) 3653–3657. [DOI] [PMID: 12788776]
5.  Esquirol, L., Peat, T.S., Wilding, M., Liu, J.W., French, N.G., Hartley, C.J., Onagi, H., Nebl, T., Easton, C.J., Newman, J. and Scott, C. An unexpected vestigial protein complex reveals the evolutionary origins of an s-triazine catabolic enzyme. J. Biol. Chem. 293 (2018) 7880–7891. [DOI] [PMID: 29523689]
[EC 3.5.2.15 created 2000, modified 2008, modified 2019]
 
 
*EC 4.3.1.3
Accepted name: histidine ammonia-lyase
Reaction: L-histidine = urocanate + NH3
For diagram of histidine catabolism, click here
Glossary: urocanate = (E)-3-(imidazol-4-yl)propenoate
Other name(s): histidase; histidinase; histidine α-deaminase; L-histidine ammonia-lyase
Systematic name: L-histidine ammonia-lyase (urocanate-forming)
Comments: This enzyme is a member of the aromatic amino acid lyase family, other members of which are EC 4.3.1.23 (tyrosine ammonia-lyase), EC 4.3.1.24 (phenylalanine ammonia-lyase) and EC 4.3.1.25 (phenylalanine/tyrosine ammonia-lyase). The enzyme contains the cofactor 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO), which is common to this family [4]. This unique cofactor is formed autocatalytically by cyclization and dehydration of the three amino-acid residues alanine, serine and glycine [5]. This enzyme catalyses the first step in the degradation of histidine and the product, urocanic acid, is further metabolized to glutamate [2,3].
Links to other databases: BRENDA, EXPASY, Gene, GTD, KEGG, PDB, CAS registry number: 9013-75-6
References:
1.  Mehler, A.H. and Tabor, H. Deamination of histidine to form urocanic acid in liver. J. Biol. Chem. 201 (1953) 775–784. [PMID: 13061415]
2.  Watts, K.T., Mijts, B.N., Lee, P.C., Manning, A.J. and Schmidt-Dannert, C. Discovery of a substrate selectivity switch in tyrosine ammonia-lyase, a member of the aromatic amino acid lyase family. Chem. Biol. 13 (2006) 1317–1326. [DOI] [PMID: 17185227]
3.  Poppe, L. and Rétey, J. Friedel-Crafts-type mechanism for the enzymatic elimination of ammonia from histidine and phenylalanine. Angew. Chem. Int. Ed. Engl. 44 (2005) 3668–3688. [DOI] [PMID: 15906398]
4.  Louie, G.V., Bowman, M.E., Moffitt, M.C., Baiga, T.J., Moore, B.S. and Noel, J.P. Structural determinants and modulation of substrate specificity in phenylalanine-tyrosine ammonia-lyases. Chem. Biol. 13 (2006) 1327–1338. [DOI] [PMID: 17185228]
5.  Schwede, T.F., Rétey, J. and Schulz, G.E. Crystal structure of histidine ammonia-lyase revealing a novel polypeptide modification as the catalytic electrophile. Biochemistry 38 (1999) 5355–5361. [DOI] [PMID: 10220322]
[EC 4.3.1.3 created 1961, modified 2008]
 
 
EC 4.3.1.5
Transferred entry: phenylalanine ammonia-lyase. Now divided into EC 4.3.1.23 (tyrosine ammonia-lyase), EC 4.3.1.24 (phenylalanine ammonia-lyase) and EC 4.3.1.25 (phenylalanine/tyrosine ammonia-lyase)
[EC 4.3.1.5 created 1965, deleted 2008]
 
 
EC 4.3.1.11
Deleted entry: dihydroxyphenylalanine ammonia-lyase. The entry had been drafted on the basis of a single abstract that did not provide experimental evidence of the enzyme-catalysed reaction
[EC 4.3.1.11 created 1972, deleted 2007]
 
 
EC 4.3.1.22
Accepted name: 3,4-dihydroxyphenylalanine reductive deaminase
Reaction: L-dopa + NADH = 3,4-dihydroxyphenylpropanoate + NAD+ + NH3
Glossary: L-dopa = 3,4-dihydroxy-L-phenylalanine
Other name(s): reductive deaminase; DOPA-reductive deaminase; DOPARDA
Systematic name: 3,4-dihydroxy-L-phenylalanine ammonia-lyase (3,4-dihydroxyphenylpropanoate-forming)
Comments: Forms part of the L-phenylalanine-catabolism pathway in the anoxygenic phototrophic bacterium Rhodobacter sphaeroides OU5. NADPH is oxidized more slowly than NADH.
Links to other databases: BRENDA, EXPASY, KEGG
References:
1.  Ranjith, N.K., Sasikala, Ch. and Ramana, Ch.V. Catabolism of L-phenylalanine and L-tyrosine by Rhodobacter sphaeroides OU5 occurs through 3,4-dihydroxyphenylalanine. Res. Microbiol. 158 (2007) 506–511. [DOI] [PMID: 17616348]
[EC 4.3.1.22 created 2007]
 
 
EC 4.3.1.23
Accepted name: tyrosine ammonia-lyase
Reaction: L-tyrosine = trans-p-hydroxycinnamate + NH3
Other name(s): TAL; tyrase; L-tyrosine ammonia-lyase
Systematic name: L-tyrosine ammonia-lyase (trans-p-hydroxycinnamate-forming)
Comments: This enzyme is a member of the aromatic amino acid lyase family, other members of which are EC 4.3.1.3 (histidine ammonia-lyase), EC 4.3.1.24 (phenylalanine ammonia-lyase) and EC 4.3.1.25 (phenylalanine/tyrosine ammonia-lyase). The enzyme contains the cofactor 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO), which is common to this family [1]. This unique cofactor is formed autocatalytically by cyclization and dehydration of the three amino-acid residues alanine, serine and glycine [3]. The enzyme is far more active with tyrosine than with phenylalanine as substrate, but the substrate specificity can be switched by mutation of a single amino acid (H89F) in the enzyme from the bacterium Rhodobacter sphaeroides [1,2].
Links to other databases: BRENDA, EXPASY, Gene, KEGG, PDB, CAS registry number: 1030840-68-6
References:
1.  Louie, G.V., Bowman, M.E., Moffitt, M.C., Baiga, T.J., Moore, B.S. and Noel, J.P. Structural determinants and modulation of substrate specificity in phenylalanine-tyrosine ammonia-lyases. Chem. Biol. 13 (2006) 1327–1338. [DOI] [PMID: 17185228]
2.  Watts, K.T., Mijts, B.N., Lee, P.C., Manning, A.J. and Schmidt-Dannert, C. Discovery of a substrate selectivity switch in tyrosine ammonia-lyase, a member of the aromatic amino acid lyase family. Chem. Biol. 13 (2006) 1317–1326. [DOI] [PMID: 17185227]
3.  Schwede, T.F., Rétey, J. and Schulz, G.E. Crystal structure of histidine ammonia-lyase revealing a novel polypeptide modification as the catalytic electrophile. Biochemistry 38 (1999) 5355–5361. [DOI] [PMID: 10220322]
[EC 4.3.1.23 created 2008 (EC 4.3.1.5 created 1965, part-incorporated 2008)]
 
 
EC 4.3.1.24
Accepted name: phenylalanine ammonia-lyase
Reaction: L-phenylalanine = trans-cinnamate + NH3
For diagram of chalcone and stilbene biosynthesis, click here
Other name(s): phenylalanine deaminase; phenylalanine ammonium-lyase; PAL; L-phenylalanine ammonia-lyase; Phe ammonia-lyase
Systematic name: L-phenylalanine ammonia-lyase (trans-cinnamate-forming)
Comments: This enzyme is a member of the aromatic amino acid lyase family, other members of which are EC 4.3.1.3 (histidine ammonia-lyase) and EC 4.3.1.23 (tyrosine ammonia-lyase) and EC 4.3.1.25 (phenylalanine/tyrosine ammonia-lyase). The enzyme contains the cofactor 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO), which is common to this family [3]. This unique cofactor is formed autocatalytically by cyclization and dehydration of the three amino-acid residues alanine, serine and glycine [9]. The enzyme from some species is highly specific for phenylalanine [7,8].
Links to other databases: BRENDA, EXPASY, Gene, KEGG, PDB, CAS registry number: 9024-28-6
References:
1.  Koukol, J. and Conn, E.E. The metabolism of aromatic compounds in higher plants. IV. Purification and properties of the phenylalanine deaminase of Hordeum vulgare. J. Biol. Chem. 236 (1961) 2692–2698. [PMID: 14458851]
2.  Young, M.R. and Neish, A.C. Properties of the ammonia-lyases deaminating phenylalanine and related compounds in Triticum sestivum and Pteridium aquilinum. Phytochemistry 5 (1966) 1121–1132.
3.  Louie, G.V., Bowman, M.E., Moffitt, M.C., Baiga, T.J., Moore, B.S. and Noel, J.P. Structural determinants and modulation of substrate specificity in phenylalanine-tyrosine ammonia-lyases. Chem. Biol. 13 (2006) 1327–1338. [DOI] [PMID: 17185228]
4.  Calabrese, J.C., Jordan, D.B., Boodhoo, A., Sariaslani, S. and Vannelli, T. Crystal structure of phenylalanine ammonia lyase: multiple helix dipoles implicated in catalysis. Biochemistry 43 (2004) 11403–11416. [DOI] [PMID: 15350127]
5.  Ritter, H. and Schulz, G.E. Structural basis for the entrance into the phenylpropanoid metabolism catalyzed by phenylalanine ammonia-lyase. Plant Cell 16 (2004) 3426–3436. [DOI] [PMID: 15548745]
6.  Watts, K.T., Mijts, B.N., Lee, P.C., Manning, A.J. and Schmidt-Dannert, C. Discovery of a substrate selectivity switch in tyrosine ammonia-lyase, a member of the aromatic amino acid lyase family. Chem. Biol. 13 (2006) 1317–1326. [DOI] [PMID: 17185227]
7.  Appert, C., Logemann, E., Hahlbrock, K., Schmid, J. and Amrhein, N. Structural and catalytic properties of the four phenylalanine ammonia-lyase isoenzymes from parsley (Petroselinum crispum Nym.). Eur. J. Biochem. 225 (1994) 491–499. [DOI] [PMID: 7925471]
8.  Cochrane, F.C., Davin, L.B. and Lewis, N.G. The Arabidopsis phenylalanine ammonia lyase gene family: kinetic characterization of the four PAL isoforms. Phytochemistry 65 (2004) 1557–1564. [DOI] [PMID: 15276452]
9.  Schwede, T.F., Rétey, J. and Schulz, G.E. Crystal structure of histidine ammonia-lyase revealing a novel polypeptide modification as the catalytic electrophile. Biochemistry 38 (1999) 5355–5361. [DOI] [PMID: 10220322]
[EC 4.3.1.24 created 2008 (EC 4.3.1.5 created 1965, part-incorporated 2008)]
 
 
EC 4.3.1.25
Accepted name: phenylalanine/tyrosine ammonia-lyase
Reaction: (1) L-phenylalanine = trans-cinnamate + NH3
(2) L-tyrosine = trans-p-hydroxycinnamate + NH3
For diagram of chalcone and stilbene biosynthesis, click here
Other name(s): PTAL; bifunctional PAL
Systematic name: L-phenylalanine(or L-tyrosine):trans-cinnamate(or trans-p-hydroxycinnamate) ammonia-lyase
Comments: This enzyme is a member of the aromatic amino acid lyase family, other members of which are EC 4.3.1.3 (histidine ammonia-lyase), EC 4.3.1.23 (tyrosine ammonia-lyase) and EC 4.3.1.24 (phenylalanine ammonia-lyase). The enzyme from some monocots, including maize, and from the yeast Rhodosporidium toruloides, deaminate L-phenylalanine and L-tyrosine with similar catalytic efficiency [3]. The enzyme contains the cofactor 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO), which is common to this family [3]. This unique cofactor is formed autocatalytically by cyclization and dehydration of the three amino-acid residues alanine, serine and glycine [4].
Links to other databases: BRENDA, EXPASY, Gene, KEGG, PDB
References:
1.  Rösler, J., Krekel, F., Amrhein, N. and Schmid, J. Maize phenylalanine ammonia-lyase has tyrosine ammonia-lyase activity. Plant Physiol. 113 (1997) 175–179. [PMID: 9008393]
2.  Watts, K.T., Mijts, B.N., Lee, P.C., Manning, A.J. and Schmidt-Dannert, C. Discovery of a substrate selectivity switch in tyrosine ammonia-lyase, a member of the aromatic amino acid lyase family. Chem. Biol. 13 (2006) 1317–1326. [DOI] [PMID: 17185227]
3.  Louie, G.V., Bowman, M.E., Moffitt, M.C., Baiga, T.J., Moore, B.S. and Noel, J.P. Structural determinants and modulation of substrate specificity in phenylalanine-tyrosine ammonia-lyases. Chem. Biol. 13 (2006) 1327–1338. [DOI] [PMID: 17185228]
4.  Schwede, T.F., Rétey, J. and Schulz, G.E. Crystal structure of histidine ammonia-lyase revealing a novel polypeptide modification as the catalytic electrophile. Biochemistry 38 (1999) 5355–5361. [DOI] [PMID: 10220322]
[EC 4.3.1.25 created 2008 (EC 4.3.1.5 created 1965, part-incorporated 2008)]
 
 
EC 5.1.3.23
Accepted name: UDP-2,3-diacetamido-2,3-dideoxyglucuronic acid 2-epimerase
Reaction: UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucuronate = UDP-2,3-diacetamido-2,3-dideoxy-α-D-mannuronate
For diagram of UDP-2,3-diacetamido-2,3-dideoxy-D-mannuronate biosynthesis, click here
Glossary: UDP-α-D-GlcNAc3NAcA = UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucuronic acid
UDP-α-D-ManNAc3NAcA = UDP-2,3-diacetamido-2,3-dideoxy-α-D-mannuronic acid
Other name(s): UDP-GlcNAc3NAcA 2-epimerase; UDP-α-D-GlcNAc3NAcA 2-epimerase; 2,3-diacetamido-2,3-dideoxy-α-D-glucuronic acid 2-epimerase; WbpI; WlbD
Systematic name: 2,3-diacetamido-2,3-dideoxy-α-D-glucuronate 2-epimerase
Comments: This enzyme participates in the biosynthetic pathway for UDP-α-D-ManNAc3NAcA (UDP-2,3-diacetamido-2,3-dideoxy-α-D-mannuronic acid), an important precursor of the B-band lipopolysaccharide of Pseudomonas aeroginosa serotype O5 and of the band-A trisaccharide of Bordetella pertussis, both important respiratory pathogens [1]. The enzyme is highly specific as UDP-α-D-GlcNAc, UDP-α-D-GlcNAcA (UDP-2-acetamido-2-deoxy-α-D-glucuronic acid) and UDP-α-D-GlcNAc3NAc (UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucose) cannot act as substrates [1].
Links to other databases: BRENDA, EXPASY, Gene, KEGG
References:
1.  Westman, E.L., McNally, D.J., Rejzek, M., Miller, W.L., Kannathasan, V.S., Preston, A., Maskell, D.J., Field, R.A., Brisson, J.R. and Lam, J.S. Identification and biochemical characterization of two novel UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucuronic acid 2-epimerases from respiratory pathogens. Biochem. J. 405 (2007) 123–130. [DOI] [PMID: 17346239]
2.  Westman, E.L., McNally, D.J., Rejzek, M., Miller, W.L., Kannathasan, V.S., Preston, A., Maskell, D.J., Field, R.A., Brisson, J.R. and Lam, J.S. Erratum report: Identification and biochemical characterization of two novel UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucuronic acid 2-epimerases from respiratory pathogens. Biochem. J. 405 (2007) 625.
3.  Sri Kannathasan, V., Staines, A.G., Dong, C.J., Field, R.A., Preston, A.G., Maskell, D.J. and Naismith, J.H. Overexpression, purification, crystallization and data collection on the Bordetella pertussis wlbD gene product, a putative UDP-GlcNAc 2′-epimerase. Acta Crystallogr. D Biol. Crystallogr. 57 (2001) 1310–1312. [PMID: 11526328]
[EC 5.1.3.23 created 2007]
 
 


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