Physiological function and regulation of flavocytochrome c3, the soluble fumarate reductase from Shewanella putrefaciens NCIMB 400.
Shewanella putrefaciens produces a soluble flavocytochrome c under anaerobic growth conditions. This protein shares sequence similarity with the catalytic subunits of membrane-bound fumarate reductases from Escherichia coli and other bacteria and the purified protein has fumarate reductase activity. It is shown here that this enzyme, flavocytochrome c3, is essential for fumarate respiration in vivo since disruption of the chromosomal fccA gene, which encodes flavocytochrome c3, leads to a specific loss of the ability to grow with fumarate as terminal electron acceptor. Growth with nitrate, trimethylamine N-oxide (TMAO) and other acceptors was unaffected. The fccA gene is transcribed as a 2 kb monocistronic mRNA. An adjacent reading frame that bears limited sequence similarity to one of the membrane anchor subunits of E. coli fumarate reductase is not co-transcribed with fccA. Expression of the fccA gene is regulated by anaerobiosis and by the availability of alternative electron acceptors, particularly nitrate and TMAO. DNA sequences have been identified that are required for this regulation.
Gordon
Euan H J
EHJ
Institute of Cell and Molecular BiologyMayfield Road, Edinburgh EH9 3JR, UK.
Pealing
Sara L
SL
Institute of Cell and Molecular BiologyMayfield Road, Edinburgh EH9 3JR, UK.
Chapman
Stephen K
SK
Department of Chemistry University of Edinburgh, Mayfield Road, Edinburgh EH9 3JR, UK.
Ward
F Bruce
FB
Institute of Cell and Molecular BiologyMayfield Road, Edinburgh EH9 3JR, UK.
Reid
Graeme A
GA
Institute of Cell and Molecular BiologyMayfield Road, Edinburgh EH9 3JR, UK.
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence / Q000235:genetics; D015139:Blotting, Southern; D015153:Blotting, Western; D003574:Cytochrome c Group / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004274:DNA, Recombinant / Q000235:genetics; D004285:Dogs; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D006089:Gram-Negative Anaerobic Bacteria / Q000201:enzymology* / Q000235:genetics; D010641:Phenotype; D011994:Recombinant Proteins / Q000235:genetics; D013385:Succinate Dehydrogenase / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
D001426:Bacterial Proteins; D003574:Cytochrome c Group; D004274:DNA, Recombinant; D011994:Recombinant Proteins; C112400:flavocytochrome c3; D013385:Succinate Dehydrogenase