Function of Ech hydrogenase in ferredoxin-dependent, membrane-bound electron transport in Methanosarcina mazei.
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 a Methanosarcina mazei Delta ech 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 C(1) compounds.
Welte
Cornelia
C
Institute of Microbiology and Biotechnology, University of Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany.
Kallnik
Verena
V
Grapp
Marcel
M
Bender
Gunes
G
Ragsdale
Steve
S
Deppenmeier
Uwe
U
D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism*; D004579:Electron Transport / Q000502:physiology; D005288:Ferredoxins / Q000378:metabolism*; D008566:Membranes / Q000378:metabolism*; D017020:Methanosarcina / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D009154:Mutation; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*
D019843:Archaeal Proteins; D005288:Ferredoxins; D010088:Oxidoreductases; C400203:Ech hydrogenase