The cytochrome bc1 and cytochrome c oxidase complexes associate to form a single supracomplex in yeast mitochondria

• Published in: The Journal of biological chemistry Vol. 275; no. 24; pp. 18093 - 18098
• Main Authors: Cruciat, C M, Brunner, S, Baumann, F, Neupert, W, Stuart, R A
• Format: Journal Article
• Language: English
• Published: United States 16.06.2000
• Subjects: Electron Transport; Electron Transport Complex III - metabolism; Electron Transport Complex IV - metabolism; Electrophoresis, Polyacrylamide Gel; Intracellular Membranes - enzymology; Macromolecular Substances; Mitochondria - enzymology; Molecular Weight; Protein Conformation; Yeasts
• ISSN: 0021-9258
• DOI: 10.1074/jbc.M001901200

The mitochondrial electron transport chain complexes are large multisubunit complexes embedded in the inner membrane. We report here that in the yeast Saccharomyces cerevisiae, the cytochrome bc(1) and cytochrome c oxidase complexes co-exist as a larger complex of approximately 1000 kDa in the mitochondrial membrane. Following solubilization with a mild detergent, the cytochrome bc(1)-cytochrome c oxidase complex remains stable. It was analyzed using the techniques of gel filtration and blue native-polyacrylamide gel electrophoresis. Direct physical association of subunits of the cytochrome bc(1) complex with those of the cytochrome c oxidase complex was verified by co-immunoprecipitation analysis. Our data indicate that the cytochrome bc(1) complex is exclusively in association with the cytochrome c oxidase complex in yeast mitochondria. We term this complex the cytochrome bc(1)-cytochrome c oxidase supracomplex.