Ferredoxin‐dependent methane formation from acetate in cell extracts of Methanosarcina barkeri (strain MS)

FEBS Letters

Thauer, R.K.¹  Fischer, R.¹ 

[1] Laboratorium für Mikrobiologie, Fachbereich Biologie, Philipps-Universität, Karl-von-Frisch-Straße, D-3550 Marburg, FRG

关键词: Methanogenesis from acetate;    Acetyl-CoA;    Ferredoxin;    Coenzyme M;    Carbon monoxide dehydrogenase;    Methanosarcina barkeri;   

DOI  :  10.1016/0014-5793(90)81195-T

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Cell extracts of Methanosarcina barkeri grown on acetate catalyzed the conversion of acetyl-CoA to CO₂ and CH₄ at a specific rate of 50 nmol·min⁻¹·mg⁻¹. When ferredoxin was removed from the extracts by DEAE-Sephacel anion exchange chromatography, the extracts were inactive but full activity was restored upon addition of purified ferredoxin from M. barkeri or from Clostridiwn pasteurianum. The apparent K_m for ferredoxin from M. barkeri was determined to be 2.5 μM. A ferredoxin dependence was also found for the formation of CO₂, H₂ and methylcoenzyme M from acetyl-CoA, when methane formation was inhibited by bromoethanesulfonate. Reduction of methyl-coenzyme M with H₂ did not require ferredoxin. These and other data indicate that ferredoxin is involved as electron carrier in methanogenesis from acetate. Methanogenesis from acetyl-CoA in cell extracts was not dependent on the membrane fraction, which contains the cytochromes.

【 授权许可】

Unknown