Wolinella succinogenes fumarate reductase contains a dihaem cytochrome b.
Article Details
- CitationCopy to clipboard
Kortner C, Lauterbach F, Tripier D, Unden G, Kroger A
Wolinella succinogenes fumarate reductase contains a dihaem cytochrome b.
Mol Microbiol. 1990 May;4(5):855-60.
- PubMed ID
- 2388563 [ View in PubMed]
- Abstract
The fumarate reductase operon of Wolinella succinogenes is made up of three structural genes (frd-CAB). The frdC gene was located next to the promoter region and identified as the cytochrome b structural gene encoding 256 amino acid residues. The N-terminal amino acid sequences of seven fragments derived from the cytochrome b moiety of the enzyme all mapped within the frdC gene. This suggested that the enzyme contained only one species of cytochrome b. Re-evaluation of earlier measurements of subunit composition, haem B content and molecular weight led to the conclusion that the enzyme contained one molecule of cytochrome b with two haem B groups. The hydropathy plot of the amino acid sequence predicted five membrane-spanning hydrophobic segments, the first four of which contained a single histidine residue each. These residues could form the axial ligands to the two haem B groups. FrdC was found to be homologous with the cytochrome b (SdhC) of the Bacillus subtilis succinate dehydrogenase, but not with the hydrophobic subunits of the fumarate reductase or succinate dehydrogenase of Escherichia coli.