title: Properties of cytoplasmic mutants of Saccharomyces cerevisiae with specific lesions in cytochrome oxidase.
abstract: Two mutants with specific defects in cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase; EC 1.9.3.1) have been isolated from cultures of Saccharomyces cerevisiae exposed to the mutagens ethyl-methane sulfonate and Mn++. The mutations have been shown to be extranuclear by two criteria. The phenotype persists in diploids formed by a cross with a p-o strain of yeast of the opposite mating type. Tetrad analysis indicates a non-Mendelian segregation (4:0 and 0:4) of the mutations. Both mutants show a total absence of cytochrome oxidase activity and of spectral cytochromes a and as. One of the mutants has been shown to be missing a polypeptide synthesized by mitochondria. The migration of this protein on polyacrylamide gels corresponds to the highest-molecular-weight subunit of cytochrome oxidase.
mesh_terms: D004171:Diploidy; D003576:Electron Transport Complex IV / Q000096:biosynthesis; D004591:Electrophoresis, Polyacrylamide Gel; D005020:Ethyl Methanesulfonate / Q000494:pharmacology; D005111:Extrachromosomal Inheritance; D005816:Genetic Complementation Test; D005827:Genetics, Microbial; D046911:Macromolecular Substances; D008345:Manganese / Q000494:pharmacology; D008928:Mitochondria / Q000032:analysis / Q000201:enzymology*; D009154:Mutation; D010455:Peptides / Q000032:analysis; D012441:Saccharomyces cerevisiae / Q000032:analysis / Q000187:drug effects / Q000201:enzymology* / Q000648:ultrastructure
chemical_list: D046911:Macromolecular Substances; D010455:Peptides; D008345:Manganese; D005020:Ethyl Methanesulfonate; D003576:Electron Transport Complex IV