Genetic analysis of the archaeon Methanosarcina barkeri Fusaro reveals a central role for Ech hydrogenase and ferredoxin in methanogenesis and carbon fixation.

ABSTRACT: Ech hydrogenase (Ech) from the methanogenic archaeon Methanosarcina barkeri catalyzes the reversible reduction of ferredoxin by H(2) and is a member of a distinct group of membrane-bound [NiFe] hydrogenases with sequence similarity to energy-conserving NADH:quinone oxidoreductase (complex I). To elucidate the physiological role(s) of Ech a mutant lacking this enzyme was constructed. The mutant was unable to grow on methanol/H(2)/CO(2), H(2)/CO(2), or acetate as carbon and energy sources but showed wild-type growth rates with methanol as sole substrate. Addition of pyruvate to the growth medium restored growth on methanol/H(2)/CO(2) but not on H(2)/CO(2) or acetate. Results obtained from growth experiments, cell suspension experiments, and enzyme activity measurements in cell extracts provi

SUBMITTER: Meuer J 

PROVIDER: S-EPMC122822 | biostudies-literature | 2002 Apr

REPOSITORIES: biostudies-literature