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.

• PMID: 218939
• PubMed
• PubTator

Reference Type

Journal Article | Research Support, U.S. Gov't, P.H.S.

Authors

Alexander NJ, Vincent RD, Perlman PS, Miller DH, Hanson DK, Mahler HR

Primary Lit For

Additional Lit For

Review For