EC - Pyridinium-3,5-bisthiocarboxylic acid mononucleotide synthase

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IntEnz Enzyme Nomenclature


Accepted name:
pyridinium-3,5-bisthiocarboxylic acid mononucleotide synthase
Other names:
P2CMN sulfurtransferase
pyridinium-3,5-biscarboxylic acid mononucleotide sulfurtransferase
P2TMN synthase
Systematic name:
[LarE]-S-[1-(5-O-phosphono-β-D-ribofuranosyl)-5-(sulfanylcarbonyl)pyridinium-3-carbonyl]-L-cysteine pyridinium-3,5-bisthiocarboxylate-mononucleotide-lyase (ATP consuming)



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

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB


  1. Desguin, B., Goffin, P., Viaene, E., Kleerebezem, M., Martin-Diaconescu, V., Maroney, M. J., Declercq, J. P., Soumillion, P., Hols, P.
    Lactate racemase is a nickel-dependent enzyme activated by a widespread maturation system.
    Nat Commun 5 : 3615 (2014). [PMID: 24710389]
  2. Desguin, B., Soumillion, P., Hols, P., Hausinger, R. P.
    Nickel-pincer cofactor biosynthesis involves LarB-catalyzed pyridinium carboxylation and LarE-dependent sacrificial sulfur insertion.
    Proc. Natl. Acad. Sci. U.S.A. 113 : 5598-5603 (2016). [PMID: 27114550]
  3. Fellner, M., Desguin, B., Hausinger, R. P., 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. U.S.A. 114 : 9074-9079 (2017). [PMID: 28784764]

[EC created 2018]