High impact information on Coenzyme M-HTP heterodisulfide

• The known crystal structures of the inactive nickel (II) enzyme in complex with coenzyme M and coenzyme B (MCR-ox1-silent) and in complex with the heterodisulfide CoM-S-S-CoB (MCR-silent) were now refined at 1.16 A and 1.8 A resolution, respectively [1].
• Methyl-coenzyme M reductase (MCR) catalyzes the final reaction of the energy conserving pathway of methanogenic archaea in which methylcoenzyme M and coenzyme B are converted to methane and the heterodisulfide CoM-S-S-CoB [1].
• The membrane-bound H2:heterodisulfide oxidoreductase system of the methanogenic archaeon Methanosarcina mazei Gö1 catalyzed the H2-dependent reduction of 2-hydroxyphenazine and the dihydro-2-hydroxyphenazine-dependent reduction of the heterodisulfide of HS-CoM and HS-CoB (CoM-S-S-CoB) [2].
• The central reaction in the energy metabolism of all methanogens studied so far, the reduction of CoM-S-S-CoB, was catalysed with high specific activity by a cell-free system [3].
• The values were determined by analyzing the concentrations of CoM-S-S-CoB, HS-CoM and HS-CoB in methane-forming cells operating under a variety of hydrogen partial pressures [4].

Biological context of Coenzyme M-HTP heterodisulfide

• The findings suggest that the methanogens regulate the bioenergetic machinery involved in CoM-S-S-CoB reduction and proton pumping in response to the environmental hydrogen concentrations [4].

References