This family of proteins are annotated as either enolase-phosphatases
or putative enolase-phosphatases.
The methionine salvage pathway converts the methylthioribose moiety of 5'-(methylthio)-adenosine to methionine via a series of biochemical steps in a wide variety of organisms. One enzyme active in this pathway is a bifunctional enolase-phosphatase called E-1 that promotes oxidative cleavage of the synthetic substrate 2,3-diketo-1-phosphohexane to 2-keto-pentanoate; it has been purified from the Gram-negative bacterium Klebsiella pneumoniae [1]. The unusual metabolite 2,3-diketo-5-methylthio-1-phosphopentane is oxidatively cleaved to yield formate (from C-1), 2-keto-4-methylthiobutyrate (the transamination product of methionine), and 3-methylthiopropionate by E-1. The native enzyme is a monomeric protein of M(r) 27,000 requiring magnesium ion as a cofactor [1]. The cloning and analysis of E-1 from Klebsiella oxytoca has been reported [2].
Myers RW, Wray JW, Fish S, Abeles RH.
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 24785-91 1993
[PubMed: 8227039] http://intl.jbc.org/cgi/content/abstract/268/33/24785
2.
Balakrishnan R, Frohlich M, Rahaim PT, Backman K, Yocum RR.
Appendix. Cloning and sequence of the gene encoding enzyme E-1 from the methionine salvage pathway of Klebsiella oxytoca.
J. Biol. Chem. 268 24792-5 1993
[PubMed: 8227040] http://intl.jbc.org/cgi/reprint/268/33/24792.pdf
Wang H, Pang H, Bartlam M, 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 2005 917-26
[PubMed: 15843022] http://dx.doi.org/10.1016/j.jmb.2005.01.072