Reaction: 2-mercaptoethanesulfonate + acetoacetate + NADP+ = 2-(2-oxopropylthio)ethanesulfonate + CO2 + NADPH
For diagram click here.
Glossary:
coenzyme M (CoM) = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated)
Other name(s): NADPH:2-(2-ketopropylthio)ethanesulfonate oxidoreductase/carboxylase; NADPH:2-ketopropyl-coenzyme M oxidoreductase/carboxylase
Systematic name: 2-mercaptoethanesulfonate,acetoacetate:NADP+ oxidoreductase (decarboxylating)
Comments: Also acts on thioethers longer in chain length on the oxo side, e.g. 2-oxobutyl-CoM, but this portion must be attached to CoM (2-mercaptoethanesulfonate); no CoM analogs will substitute. This enzyme forms component II of a four-component enzyme system {comprising EC 4.4.1.23 (2-hydroxypropyl-CoM lyase; component I), EC 1.8.1.5 [2-oxopropyl-CoM reductase (carboxylating); component II], EC 1.1.1.268 [2-(R)-hydroxypropyl-CoM dehydrogenase; component III] and EC 1.1.1.269 [2-(S)-hydroxypropyl-CoM dehydrogenase; component IV]} that is involved in epoxyalkane carboxylation in Xanthobacter sp. strain Py2.
Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 244301-63-1
References:
1. Allen, J.R., Clark, D.D., Krum, J.G. and Ensign, S.A. A role for coenzyme M (2-mercaptoethanesulfonic acid) in a bacterial pathway of aliphatic epoxide carboxylation. Proc. Natl. Acad. Sci. USA 96 (1999) 8432-8437. [PMID: 10411892]
2. Clark, D.D., Allen, J.R. and Ensign, S.A. Characterization of five catalytic activities associated with the NADPH:2-ketopropyl-coenzyme M [2-(2-ketopropylthio)ethanesulfonate] oxidoreductase/carboxylase of the Xanthobacter strain Py2 epoxide carboxylase system. Biochemistry 39 (2000) 1294-1304. [PMID: 10684609]