EC - Acireductone synthase

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IntEnz Enzyme Nomenclature


Accepted name:
acireductone synthase
Other names:
E-1 enolase-phosphatase
Systematic name:
5-(methylsulfanyl)-2,3-dioxopentyl-phosphate phosphohydrolase (isomerizing)



This bifunctional enzyme first enolizes the substrate to form the intermediate 2-hydroxy-5-(methylsulfanyl)-3-oxopent-1-enyl phosphate, which is then dephosphorylated to form the acireductone 1,2-dihydroxy-5-(methylsulfanyl)pent-1-en-3-one [2]. The acireductone represents a branch point in the methione-salvage pathway as it is used in the formation of formate, CO and 3-(methylsulfanyl)propanoate by EC [acireductone dioxygenase (Ni2+-requiring)] and of formate and 4-(methylsulfanyl)-2-oxobutanoate either by a spontaneous reaction under aerobic conditions or by EC {acireductone dioxygenase [iron(II)-requiring]} [1,2].

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0043874
UniProtKB/Swiss-Prot: (173) [show] [UniProt]


  1. Myers, R.W., Wray, J.W., Fish, S. and Abeles, R.H.
    Purification and characterization of an enzyme involved in oxidative carbon-carbon bond cleavage reactions in the methionine salvage pathway of Klebsiella pneumoniae.
    J. Biol. Chem. 268 : 24785-24791 (1993). [PMID: 8227039]
  2. Wray, J.W. and Abeles, R.H.
    The methionine salvage pathway in Klebsiella pneumoniae and rat liver. Identification and characterization of two novel dioxygenases.
    J. Biol. Chem. 270 : 3147-3153 (1995). [PMID: 7852397]
  3. Wang, H., Pang, H., Bartlam, M. and Rao, Z.
    Crystal structure of human E1 enzyme and its complex with a substrate analog reveals the mechanism of its phosphatase/enolase activity.
    J. Mol. Biol. 348 : 917-926 (2005). [PMID: 15843022]

[EC created 2006]