InterPro domain: IPR010968

The six-subunit complex RnfABCDGE in Rhodobacter capsulatus (Rhodopseudomonas capsulata) encodes a NADH oxidoreductase responsible for electron transport to nitrogenase, necessary for nitrogen fixation [ 1 ]. A closely related complex in Escherichia coli, RsxABCDGE (Reducer of SoxR), reduces the 2Fe-2S-containing superoxide sensor SoxR, active as a transcription factor when oxidized [ 2 ]. The Rnf complex is ferredoxin:NAD+ oxidoreductase that appears to pump different ions in different bacteria. In Clostridium ljungdahlii and Desulfovibrio alaskensis functions as a proton pump whose activity is important for growth [ 3 , 4 ], whereas in Acetobacterium woodii functions as a Na(+)-translocating electron transport chain [ 5 ].

This family represents the subunit E of Rnf complexes.

1. Overexpression in Escherichia coli of the rnf genes from Rhodobacter capsulatus--characterization of two membrane-bound iron-sulfur proteins. Eur. J. Biochem. 251, 54-64
2. A reducing system of the superoxide sensor SoxR in Escherichia coli. EMBO J. 22, 2614-22
3. The Rnf complex of Clostridium ljungdahlii is a proton-translocating ferredoxin:NAD+ oxidoreductase essential for autotrophic growth. MBio 4, e00406-12
4. The role of Rnf in ion gradient formation in Desulfovibrio alaskensis. PeerJ 4, e1919
5. The ferredoxin:NAD+ oxidoreductase (Rnf) from the acetogen Acetobacterium woodii requires Na+ and is reversibly coupled to the membrane potential. J. Biol. Chem. 288, 31496-502