Random mutant generation and its utility in uncovering structural and functional features of cytochrome b in Saccharomyces cerevisiae.
The generation of random mutations in the mitochondrial cytochrome b gene of Saccharomyces cerevisiae has been used as a most fruitful means of identifying subregions that play a key role in the bc1 complex mechanism, best explained by the protonmotive Q cycle originally proposed by Peter Mitchell. Selection for center i and center o inhibitor resistance mutants, in particular, has yielded much information. The combined approaches of genetics and structural predictions have led to a two-dimensional folding model for cytochrome b that is most compatible with current knowledge of the protonmotive Q cycle. A three-dimensional model is emerging from studies of distant reversions of deficient mutants. Finally, interactions between cytochrome b and the other subunits of the bc1 complex, such as the iron-sulfur protein, can be affected by a single amino acid change.
Université Catholique de Louvain, Unité de Génétique, Belgium.
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Colson
D000595:Amino Acid Sequence; D003573:Cytochrome b Group / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D004271:DNA, Fungal / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D004352:Drug Resistance, Microbial; D004579:Electron Transport / Q000187:drug effects; D014450:Electron Transport Complex III / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D005816:Genetic Complementation Test; D005990:Glycerol / Q000494:pharmacology; D008958:Models, Molecular; D016296:Mutagenesis; D010101:Oxygen Consumption / Q000187:drug effects; D011487:Protein Conformation; D017510:Protein Folding; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D013329:Structure-Activity Relationship
D003573:Cytochrome b Group; D004271:DNA, Fungal; D004272:DNA, Mitochondrial; D005656:Fungal Proteins; D014450:Electron Transport Complex III; D005990:Glycerol