Regulatory interactions between mitochondrial genes. I. Genetic and biochemical characterization of some mutant types affecting apocytochrome b and cytochrome oxidase.
The region of the mtDNA containing the structural gene for apocytochrome b is called the cob or box region. There is evidence that the same region is also involved in the regulation of cytochrome oxidase. We have isolated eight mit- mutants in this region and have ordered them using petite deletion mapping. Four of these mutants appear to map outside the boxII region on the oli2-proximal end. Analysis of restriction endonuclease fragments of the mtDNA from peptides used in the deletion mapping suggests a minimum size of 3.1 x 10(3) base pairs for the whole cob region. Although none of our mutants contained any cytochrome b or cytochrome b-linked activities, polypeptides apparently related to apocytochrome b were present in some but not all mutants. Additional regulatory effects (both positive and negative) on cytochrome oxidase by virtue of control of its subunit I were also observed. In addition to these phenotypic traits, some of the mutants accumulated novel, mitochondrially translated polypeptides not seen in wild type.
D001059:Apoproteins / Q000096:biosynthesis*; D003580:Cytochromes / Q000096:biosynthesis*; D004262:DNA Restriction Enzymes; D004272:DNA, Mitochondrial / Q000378:metabolism*; D003576:Electron Transport Complex IV / Q000096:biosynthesis*; D005796:Genes; D009154:Mutation; D014176:Protein Biosynthesis; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D013045:Species Specificity; D014158:Transcription, Genetic
D001059:Apoproteins; D003580:Cytochromes; D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV; D004262:DNA Restriction Enzymes