Novel reactions involved in energy conservation by methanogenic archaea

FEBS Letters

Lienard, Tanja¹  Deppenmeier, Uwe¹  Gottschalk, Gerhard¹ 

[1] Institut für Mikrobiologie und Genetik, Georg-August-Universität, Grisebachstr. 8, 37077 Göttingen, Germany

关键词: Methanogenesis;    Methanophenazine;    Proton translocation;    Sodium ion translocation;    Hydrogenase;    F420H2 dehydrogenase;    CoB-SH;    7-mercaptoheptanoylthreonine phosphate;    CoM-SH;    2-mercaptoethanesulfonate;    F420;    (N-L-lactyl-γ-L-glutamyl)-L-glutamic acid phosphodiester of 7;    8-didemethyl-8-hydroxy-5-deazariboflavin-5′-phosphate;    F420H2;    reduced F420;    Mc.;    Methanococcus;    Mb.;    Methanobacterium;    Ms.;    Methanosarcina;    MF;    methanofuran;    H4MPT;    tetrahydromethanopterin;    Δμ̃ H+;    electrochemical proton gradient;    Δμ̃ Na+;    electrochemical sodium ion gradient;   

DOI  :  10.1016/S0014-5793(99)01026-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Methanogenic archaea of the order Methanosarcinales which utilize C₁ compounds such as methanol, methylamines or H₂+CO₂, employ two novel membrane-bound electron transport systems generating an electrochemical proton gradient: the H₂:heterodisulfide oxidoreductase and the F₄₂₀H₂:heterodisulfide oxidoreductase. The systems are composed of the heterodisulfide reductase and either a membrane-bound hydrogenase or a F₄₂₀H₂ dehydrogenase which is functionally homologous to the proton-translocating NADH dehydrogenase. Cytochromes and the novel electron carrier methanophenazine are also involved. In addition, the methyl-H₄MPT:HS-CoM methyltransferase is bioenergetically relevant. The enzyme couples methyl group transfer with the translocation of sodium ions and seems to be present in all methanogens. The proton-translocating systems with the participation of cytochromes and methanophenazine have been found so far only in the Methanosarcinales.

【 授权许可】

Unknown