EC |
2.5.1.76 |
Accepted name: |
cysteate synthase |
Reaction: |
O-phospho-L-serine + sulfite = L-cysteate + phosphate |
Other name(s): |
sulfite:O-phospho-L-serine sulfotransferase (phosphate-hydrolysing, L-cysteate-forming) |
Systematic name: |
sulfite:O-phospho-L-serine sulfonotransferase (phosphate-hydrolysing, L-cysteate-forming) |
Comments: |
A pyridoxal-phosphate protein. It is highly specific for O-phospho-L-serine and sulfite. The reaction proceeds through a dehydroalanine (2-aminoacrylic acid) intermediate. The enzyme from Methanosarcina acetivorans is evolutionarily related to threonine synthase (EC 4.2.3.1), but the reaction is more similar to that of O-phosphoserine sulfhydrylase (EC 2.5.1.65). |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc |
References: |
1. |
Graham, D.E., Taylor, S.M., Wolf, R.Z. and Namboori, S.C. Convergent evolution of coenzyme M biosynthesis in the Methanosarcinales: cysteate synthase evolved from an ancestral threonine synthase. Biochem. J. 424 (2009) 467–478. [DOI] [PMID: 19761441] |
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[EC 2.5.1.76 created 2009] |
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EC |
2.6.1.52 |
Accepted name: |
phosphoserine transaminase |
Reaction: |
(1) O-phospho-L-serine + 2-oxoglutarate = 3-phosphooxypyruvate + L-glutamate (2) 4-phosphooxy-L-threonine + 2-oxoglutarate = (3R)-3-hydroxy-2-oxo-4-phosphooxybutanoate + L-glutamate |
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For diagram of EC 2.6.1, click here, for diagram of serine biosynthesis, click here and for diagram of pyridoxal biosynthesis, click here |
Other name(s): |
PSAT; phosphoserine aminotransferase; 3-phosphoserine aminotransferase; hydroxypyruvic phosphate-glutamic transaminase; L-phosphoserine aminotransferase; phosphohydroxypyruvate transaminase; phosphohydroxypyruvic-glutamic transaminase; 3-O-phospho-L-serine:2-oxoglutarate aminotransferase; SerC; PdxC; 3PHP transaminase |
Systematic name: |
O-phospho-L-serine:2-oxoglutarate aminotransferase |
Comments: |
A pyridoxal 5′-phosphate protein. This enzyme catalyses the second step in the phosphorylated pathway of serine biosynthesis [1,3] and the third step in pyridoxal 5′-phosphate biosynthesis in the bacterium Escherichia coli [3]. Pyridoxal 5′-phosphate is the cofactor for both activities and therefore seems to be involved in its own biosynthesis [4]. Non-phosphorylated forms of serine and threonine are not substrates [4]. The archaeal enzyme has a relaxed specificity and can act on L-cysteate and L-alanine as alternative substrates to O-phospho-L-serine [7]. |
Links to other databases: |
BRENDA, EXPASY, GTD, KEGG, MetaCyc, PDB, CAS registry number: 9030-90-4 |
References: |
1. |
Pizer, L.I. The pathway and control of serine biosynthesis in Escherichia coli. J. Biol. Chem. 238 (1963) 3934–3944. [PMID: 14086727] |
2. |
Hirsch, H. and Greenberg, D.M. Studies on phosphoserine aminotransferase of sheep brain. J. Biol. Chem. 242 (1967) 2283–2287. [PMID: 6022873] |
3. |
Zhao, G. and Winkler, M.E. A novel α-ketoglutarate reductase activity of the serA-encoded 3-phosphoglycerate dehydrogenase of Escherichia coli K-12 and its possible implications for human 2-hydroxyglutaric aciduria. J. Bacteriol. 178 (1996) 232–239. [DOI] [PMID: 8550422] |
4. |
Drewke, C., Klein, M., Clade, D., Arenz, A., Müller, R. and Leistner, E. 4-O-phosphoryl-L-threonine, a substrate of the pdxC(serC) gene product involved in vitamin B6 biosynthesis. FEBS Lett. 390 (1996) 179–182. [DOI] [PMID: 8706854] |
5. |
Zhao, G. and Winkler, M.E. 4-Phospho-hydroxy-L-threonine is an obligatory intermediate in pyridoxal 5′-phosphate coenzyme biosynthesis in Escherichia coli K-12. FEMS Microbiol. Lett. 135 (1996) 275–280. [PMID: 8595869] |
6. |
Baek, J.Y., Jun, D.Y., Taub, D. and Kim, Y.H. Characterization of human phosphoserine aminotransferase involved in the phosphorylated pathway of L-serine biosynthesis. Biochem. J. 373 (2003) 191–200. [PMID: 12633500] |
7. |
Helgadottir, S., Rosas-Sandoval, G., Soll, D. and Graham, D.E. Biosynthesis of phosphoserine in the Methanococcales. J. Bacteriol. 189 (2007) 575–582. [PMID: 17071763] |
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[EC 2.6.1.52 created 1972, modified 2006] |
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EC |
4.1.1.15 |
Accepted name: |
glutamate decarboxylase |
Reaction: |
L-glutamate = 4-aminobutanoate + CO2 |
Glossary: |
4-aminobutanoate = γ-aminobutyrate = GABA
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Other name(s): |
L-glutamic acid decarboxylase; L-glutamic decarboxylase; cysteic acid decarboxylase; L-glutamate α-decarboxylase; aspartate 1-decarboxylase; aspartic α-decarboxylase; L-aspartate-α-decarboxylase; γ-glutamate decarboxylase; L-glutamate 1-carboxy-lyase |
Systematic name: |
L-glutamate 1-carboxy-lyase (4-aminobutanoate-forming) |
Comments: |
A pyridoxal-phosphate protein. The brain enzyme also acts on L-cysteate, 3-sulfino-L-alanine and L-aspartate. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9024-58-2 |
References: |
1. |
Ambe, L. and Sohonie, K. Purification and properties of glutamate decarboxylase from the field bean (Dolichos lablab). Enzymologia 26 (1963) 98–107. [PMID: 14081858] |
2. |
Nakano, Y. and Kitaoka, S. L-Aspartate α-decarboxylase in a cell-free system from Escherichia coli. J. Biochem. (Tokyo) 70 (1971) 327. [PMID: 4937550] |
3. |
Roberts, E. and Frankel, S. Further studies of glutamic acid decarboxylase in brain. J. Biol. Chem. 190 (1951) 505–512. [PMID: 14841200] |
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[EC 4.1.1.15 created 1961] |
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EC |
4.1.1.29 |
Accepted name: |
sulfinoalanine decarboxylase |
Reaction: |
3-sulfino-L-alanine = hypotaurine + CO2 |
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For diagram of taurine biosynthesis, click here |
Other name(s): |
cysteine-sulfinate decarboxylase; L-cysteinesulfinic acid decarboxylase; cysteine-sulfinate decarboxylase; CADCase/CSADCase; CSAD; cysteic decarboxylase; cysteinesulfinic acid decarboxylase; cysteinesulfinate decarboxylase; sulfoalanine decarboxylase; 3-sulfino-L-alanine carboxy-lyase |
Systematic name: |
3-sulfino-L-alanine carboxy-lyase (hypotaurine-forming) |
Comments: |
A pyridoxal-phosphate protein. Also acts on L-cysteate. The 1992 edition of the Enzyme List erroneously gave the name sulfoalanine decarboxylase to this enzyme. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 62213-10-9 |
References: |
1. |
Guion-Rain, M.C., Portemer, C. and Chatagner, F. Rat liver cysteine sulfinate decarboxylase: purification, new appraisal of the molecular weight and determination of catalytic properties. Biochim. Biophys. Acta 384 (1975) 265–276. [DOI] [PMID: 236774] |
2. |
Jacobsen, J.G., Thomas, L.L. and Smith, L.H., Jr. Properties and distribution of mammalian L-cysteine sulfinate carboxy-lyases. Biochim. Biophys. Acta 85 (1964) 103–116. [PMID: 14159288] |
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[EC 4.1.1.29 created 1961, deleted 1972, reinstated 1976, modified 1983, modified 1999] |
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EC |
4.1.1.122 |
Accepted name: |
L-cysteate decarboxylase |
Reaction: |
L-cysteate = taurine + CO2 |
Other name(s): |
CAD |
Systematic name: |
L-cysteate carboxy-lyase (taurine-forming) |
Comments: |
Requires pyridoxal 5′-phosphate. The enzyme, characterized from chicken, is specific for L-cysteate and has poor activity with 3-sulfino-L-alanine. cf. EC 4.1.1.29, sulfinoalanine decarboxylase. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc |
References: |
1. |
Malatesta, M., Mori, G., Acquotti, D., Campanini, B., Peracchi, A., Antin, P.B. and Percudani, R. Birth of a pathway for sulfur metabolism in early amniote evolution. Nat Ecol Evol 4 (2020) 1239–1246. [DOI] [PMID: 32601391] |
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[EC 4.1.1.122 created 2022] |
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EC |
4.4.1.10 |
Accepted name: |
cysteine lyase |
Reaction: |
L-cysteine + sulfite = L-cysteate + hydrogen sulfide |
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For diagram of taurine biosynthesis, click here |
Other name(s): |
cysteine (sulfite) lyase; L-cysteine hydrogen-sulfide-lyase (adding sulfite) |
Systematic name: |
L-cysteine hydrogen-sulfide-lyase (adding sulfite; L-cysteate-forming) |
Comments: |
A pyridoxal-phosphate protein. Can use a second molecule of cysteine (producing lanthionine), or other alkyl thiols, as a replacing agent. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 9079-86-1 |
References: |
1. |
Tolosa, E.A., Chepurnova, N.K., Khomutov, R.M. and Severin, E.S. Reactions catalysed by cysteine lyase from the yolk sac of chicken embryo. Biochim. Biophys. Acta 171 (1969) 369–371. [DOI] [PMID: 5813025] |
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[EC 4.4.1.10 created 1972] |
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EC |
4.4.1.25 |
Accepted name: |
L-cysteate sulfo-lyase |
Reaction: |
L-cysteate + H2O = hydrogensulfite + pyruvate + NH3 (overall reaction) (1a) L-cysteate = hydrogensulfite + 2-aminoprop-2-enoate (1b) 2-aminoprop-2-enoate = 2-iminopropanoate (spontaneous) (1c) 2-iminopropanoate + H2O = pyruvate + NH3 (spontaneous) |
Glossary: |
L-cysteate = (2S)-2-amino-3-sulfopropanoate |
Other name(s): |
L-cysteate sulfo-lyase (deaminating); CuyA; L-cysteate bisulfite-lyase (deaminating; pyruvate-forming) |
Systematic name: |
L-cysteate hydrogensulfite-lyase (deaminating; pyruvate-forming) |
Comments: |
A pyridoxal-phosphate protein. The enzyme cleaves a carbon-sulfur bond, releasing hydrogensulfite and an unstable enamine product that tautomerizes to an imine form, which undergoes a hydrolytic deamination to form pyruvate and ammonia. The latter reaction, which can occur spontaneously, can also be catalysed by EC 3.5.99.10, 2-iminobutanoate/2-iminopropanoate deaminase. D-Cysteine can also act as a substrate, but more slowly. It is converted into hydrogen sulfide, pyruvate, and ammonia. This inducible enzyme from the marine bacterium Silicibacter pomeroyi DSS-3 forms part of the cysteate-degradation pathway. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc |
References: |
1. |
Denger, K., Smits, T.H.M. and Cook, A.M. L-Cysteate sulpho-lyase, a widespread pyridoxal 5′-phosphate-coupled
desulphonative enzyme purified from Silicibacter pomeroyi DSS-3(T). Biochem. J. 394 (2006) 657–664. [DOI] [PMID: 16302849] |
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[EC 4.4.1.25 created 2006] |
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