A mutation in yeast mitochondrial DNA results in a precise excision of the terminal intron of the cytochrome b gene.
The yeast nuclear gene CBP2 was previously proposed to code for a protein necessary for processing of the terminal intron in the cytochrome b pre-mRNA (McGraw, P., and Tzagoloff, A. (1983) J. Biol. Chem. 258, 9459-9468). In the present study we describe a mitochondrial mutation capable of suppressing the respiratory deficiency of cbp2 mutants. The mitochondrial suppressor mutation has been shown to be the result of a precise excision of the last intervening sequence from the cytochrome b gene. Strains with the altered mitochondrial DNA have normal levels of mature cytochrome b mRNA and of cytochrome b and exhibit wild type growth on glycerol. These results confirm that CBP2 codes for a protein specifically required for splicing of the cytochrome b intron and further suggest that absence of the intervening sequence does not noticeably affect the expression of respiratory function in mitochondria.
D001483:Base Sequence; D002872:Chromosome Deletion; D003573:Cytochrome b Group / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics*; D009154:Mutation; D010101:Oxygen Consumption; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development; D013053:Spectrophotometry
D003573:Cytochrome b Group; D004272:DNA, Mitochondrial