Open AccessFunction of Ech Hydrogenase in Ferredoxin-Dependent, Membrane-Bound Electron Transport in Methanosarcina mazei
Author(s) -
Cornelia U. Welte,
Verena Kallnik,
Marcel Grapp,
Güneş Bender,
S.W. Ragsdale,
Uwe Deppenmeier
Publication year - 2010
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.01307-09
Subject(s) - ferredoxin , methanogenesis , hydrogenase , methanosarcina , methanosarcina barkeri , electron transport chain , biology , ferredoxin—nadp(+) reductase , biochemistry , electron transfer , reductase , biophysics , chemistry , enzyme , photochemistry , methane , ecology
Reduced ferredoxin is an intermediate in the methylotrophic and aceticlastic pathway of methanogenesis and donates electrons to membrane-integral proteins, which transfer electrons to the heterodisulfide reductase. A ferredoxin interaction has been observed previously for the Ech hydrogenase. Here we present a detailed analysis of aMethanosarcina mazei Δech mutant which shows decreased ferredoxin-dependent membrane-bound electron transport activity, a lower growth rate, and faster substrate consumption. Evidence is presented that a second protein whose identity is unknown oxidizes reduced ferredoxin, indicating an involvement in methanogenesis from methylated C1 compounds.