IUBMB Enzyme Nomenclature


Accepted name: pyridinium-3,5-bisthiocarboxylic acid mononucleotide synthase

Reaction: (1) [LarE]-L-cysteine + pyridin-1-ium-3,5-dicarboxylate mononucleotide + ATP = [LarE]-dehydroalanine + pyridin-1-ium-3-carboxylate-5-thiocarboxylate mononucleotide + AMP + diphosphate (overall reaction)
(1a) ATP + pyridin-1-ium-3,5-dicarboxylate mononucleotide = diphosphate + 5-carboxy-1-(5-O-phospho-β-D-ribofuranosyl)pyridin-1-ium-3-carbonyl adenylate
(1b) 5-carboxy-1-(5-O-phospho-β-D-ribofuranosyl)pyridin-1-ium-3-carbonyl adenylate + [LarE]-L-cysteine = AMP + [LarE]-S-[5-carboxy-1-(5-O-phosphono-β-D-ribofuranosyl)pyridin-1-ium-3-carbonyl]-L-cysteine
(1c) [LarE]-S-[5-carboxy-1-(5-O-phosphono-β-D-ribofuranosyl)pyridin-1-ium-3-carbonyl]-L-cysteine = [LarE]-dehydroalanine + pyridin-1-ium-3-carboxylate-5-thiocarboxylate mononucleotide
(2) [LarE]-L-cysteine + pyridin-1-ium-3-carboxylate-5-thiocarboxylate mononucleotide + ATP = [LarE]-dehydroalanine + pyridin-1-ium-3,5-bisthiocarboxylate mononucleotide + AMP + diphosphate (overall reaction)
(2a) ATP + pyridin-1-ium-3-carboxylate-5-thiocarboxylate mononucleotide = diphosphate + 1-(5-O-phospho-β-D-ribofuranosyl)-5-(sulfanylcarbonyl)pyridin-1-ium-3-carbonyl adenylate
(2b) 1-(5-O-phospho-β-D-ribofuranosyl)-5-(sulfanylcarbonyl)pyridin-1-ium-3-carbonyl adenylate + [LarE]-L-cysteine = AMP + [LarE]-S-[1-(5-O-phosphono-β-D-ribofuranosyl)-5-(sulfanylcarbonyl)pyridin-1-ium-3-carbonyl]-L-cysteine
(2c) [LarE]-S-[1-(5-O-phosphono-β-D-ribofuranosyl)-5-(sulfanylcarbonyl)pyridin-1-ium-3-carbonyl]-L-cysteine = [LarE]-dehydroalanine + pyridin-1-ium-3,5-bisthiocarboxylate mononucleotide

Other name(s): LarE; P2CMN sulfurtransferase; pyridinium-3,5-biscarboxylic acid mononucleotide sulfurtransferase; P2TMN synthase

Systematic name: [LarE]-S-[1-(5-O-phosphono-β-D-ribofuranosyl)-5-(sulfanylcarbonyl)pyridin-1-ium-3-carbonyl]-L-cysteine pyridin-1-ium-3,5-dicarbothioate-mononucleotide-lyase (ATP-consuming)

Comments: This enzyme, found in Lactobacillus plantarum, is involved in the biosynthesis of a nickel-pincer cofactor. The process starts when one enzyme molecule adenylates pyridinium-3,5-dicarboxylate mononucleotide (P2CMN) and covalently binds the adenylated product to an intrinsic cysteine residue. Next, the enzyme cleaves the carbon-sulfur bond, liberating pyridinium-3-carboxylate-5-thiocarboxylate mononucleotide (PCTMN) and leaving a 2-aminoprop-2-enoate (dehydroalanine) residue attached to the protein. Since the cysteine residue is not regenerated in vivo, the enzyme is inactivated during the process. A second enzyme molecule then repeats the process with PCTMN, adenylating it and covalently binding it to the same cysteine residue, followed by liberation of pyridinium-3,5-bisthiocarboxylate mononucleotide (P2TMN) and the inactivation of the second enzyme molecule.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:


1. Desguin, B., Goffin, P., Viaene, E., Kleerebezem, M., Martin-Diaconescu, V., Maroney, M.J., Declercq, J.P., Soumillion, P. and Hols, P. Lactate racemase is a nickel-dependent enzyme activated by a widespread maturation system. Nat Commun 5 (2014) 3615. [PMID: 24710389]

2. Desguin, B., Soumillion, P., Hols, P. and Hausinger, R.P. Nickel-pincer cofactor biosynthesis involves LarB-catalyzed pyridinium carboxylation and LarE-dependent sacrificial sulfur insertion. Proc. Natl Acad. Sci. USA 113 (2016) 5598-5603. [PMID: 27114550]

3. Fellner, M., Desguin, B., Hausinger, R.P. and Hu, J. Structural insights into the catalytic mechanism of a sacrificial sulfur insertase of the N-type ATP pyrophosphatase family, LarE. Proc. Natl Acad. Sci. USA 114 (2017) 9074-9079. [PMID: 28784764]

[EC created 2018]

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