Is cytochrome b really the antimycin-binding component of the cytochrome b--c1 complex of yeast mitochondria.
1. The antimycin binding sites were found to be independent of cytochrome(s) b synthesis in pseudo-wild-type revertants of cytochrome b mutants. These revertants, whose primary mutation is located in the introns of the cob-box gene of mitochondrial DNA, have modified contents of cytochromes b-562 and b-565 and fully functional respiratory chain. 2. Missense mutations in three genetic loci allocated to the exons of the cytochrome b gene, abolish the strong affinity binding of antimycin. 3. It is proposed that the antimycin-binding component is not cytochrome b itself, but interacts with it in such a way that an alteration of the cytochrome b structure affects the antimycin-binding site.
D000968:Antimycin A / Q000378:metabolism*; D001665:Binding Sites; D001667:Binding, Competitive; D003573:Cytochrome b Group / Q000235:genetics / Q000378:metabolism*; D014450:Electron Transport Complex III; D008928:Mitochondria / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism*; D009154:Mutation; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D011808:Quinone Reductases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*
D003573:Cytochrome b Group; D009097:Multienzyme Complexes; D000968:Antimycin A; D009247:NADH, NADPH Oxidoreductases; D011808:Quinone Reductases; D014450:Electron Transport Complex III