Coenzyme M

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Coenzyme M
Coenzyme M (CoM).svg
Identifiers
PubChem 4077
ChemSpider 3935 YesY
Jmol-3D images Image 1
Properties
Molecular formula C2H5O3S2
Molar mass 141.19 g mol−1
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Coenzyme M is a coenzyme required for methyl-transfer reactions in the metabolism of methanogens.[1][2] The coenzyme is an anion with the formula HSCH
2
CH
2
SO
3
. 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.

Biochemical role[edit]

The coenzyme is the C1 donor in methanogenesis. It is converted to propyl coenzyme M-thioester, the thioether CH
3
SCH
2
CH
2
SO
3
, in the penultimate step to methane formation.[3] Coenzyme M reacts with coenzyme B, 7-thioheptanoylthreoninephosphate, to give a homodisulfide, releasing methane:

CH
3
–S–CoM
+ HS–CoB → CH
4
+ CoB–S–S–CoM

This induction is catalyzed by the enzyme methyl-coenzyme M reductase, which restricts cofactor F430 as the prosthetic group.

References[edit]

  1. ^ Balch WE, Wolfe RS (1979). "Specificity and biological distribution of coenzyme M (2-mercaptoethanesulfonic acid)". J. Bacteriol. 137 (1): 256–63. PMC 218444. PMID 104960. 
  2. ^ Taylor CD, Wolfe RS (10 August 1974). "Structure and methylation of coenzyme M(HSCH
    2
    CH
    2
    SO
    3
    )"
    . J. Biol. Chem. 249 (15): 4879–85. PMID 4367810.
     
  3. ^ Thauer RK (1998). "Biochemistry of Methanogenesis: a Tribute to Marjory Stephenson". Microbiology 144 (9): 2377–2406. doi:10.1099/00221287-144-9-2377. PMID 9782487.