Formula C11H22NO7PS | ||
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Coenzyme B is a coenzyme required for redox reactions in methanogens. The full chemical name of coenzyme B is 7-mercaptoheptanoylthreoninephosphate. The molecule contains a thiol, which is its principal site of reaction.
Coenzyme B reacts with 2-methylthioethanesulfonate (methyl-Coenzyme M, abbreviated CH
3–S–CoM), to release methane in methanogenesis:
3–S–CoM + HS–CoB → CH
4 + CoB–S–S–CoM
This conversion is catalyzed by the enzyme methyl coenzyme M reductase, which contains cofactor F430 as the prosthetic group.
A related conversion that utilizes both HS-CoB and HS-CoM is the reduction of fumarate to succinate, catalyzed by fumarate reductase:
CH3–S–CoM + HS–CoB −O
2CCH=CHCO−
2 → −O
2CCH
2–CH
2CO−
2 + CoB–S–S–CoM
References
Coenzyme B Wikipedia(Text) CC BY-SA