IntEnz

EC 3.1.3.77 - Acireductone synthase

IntEnz Enzyme Nomenclature
EC 3.1.3.77

Names

Reactions

• (1) 5-(methylthio)-2,3-dioxopentyl phosphate + H2O = 1,2-dihydroxy-5-(methylthio)pent-1-en-3-one + phosphate
•   (1a) 5-(methylsulfanyl)-2,3-dioxopentyl phosphate = 2-hydroxy-5-(methylsulfanyl)-3-oxopent-1-enyl phosphate
•   (1b) 2-hydroxy-5-(methylsulfanyl)-3-oxopent-1-enyl phosphate + H2O = 1,2-dihydroxy-5-(methylsulfanyl)pent-1-en-3-one + phosphate

Comments:

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 1.13.11.53 [acireductone dioxygenase (Ni2+-requiring)] and of formate and 4-(methylsulfanyl)-2-oxobutanoate either by a spontaneous reaction under aerobic conditions or by EC 1.13.11.54 {acireductone dioxygenase [iron(II)-requiring]} [1,2].

Links to other databases

References

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 3.1.3.77 created 2006]