Coenzyme M
From Wikipedia, the free encyclopedia
Coenzyme M is the anion with the formula HSCH2CH2SO3-. It is named 2-mercaptoethanesulfonate and abbreviated HS-CoM. The cation is unimportant, but the sodium salt is most available. Mercaptoethanesulfonate contains both a thiol, which is the main site of reactivity, and a sulfonate group, which confers solubility in aqueous media.
The coenzyme is the C1 carrier in methanogenesis. It is converted to methyl coenzyme M, the thioether CH3SCH2CH2SO3-, in the penultimate step to methane formation.[1] Coenzyme M reacts with coenzyme B, 7-thioheptanoylthreoninephosphate, to give a heterodisulfide, releasing methane:
- CH3-S-CoM + HS-CoB → CH4 + CoB-S-S-CoM
This conversion is catalyzed by the enzyme methyl coenzyme M reductase, which contains cofactor F430 as the prosthetic group.
- ^ Thauer, R. K., "Biochemistry of Methanogenesis: a Tribute to Marjory Stephenson", Microbiology, 1998, volume 144, pages 2377-2406.