Isolation and Sequencing of the RatCoq7Gene and the Mapping of MouseCoq7to Chromosome 7

We recently identified theSaccharomyces cerevisiae COQ7gene and showed that its product affects one or more monoxygenase steps in the synthesis of ubiquinone. Other investigators have independently isolated the yeastCOQ7gene asCAT5and identified it as a gene necessary for the derepression of gluconeogenic enzymes in yeast. In the present study, a homolog of the yeastCOQ7 (CAT5)gene was isolated from a rat testis cDNA library by functional complementation of acoq7deletion mutant ofS. cerevisiae.The resulting cDNA clones contained a 0.8-kb insert with an open reading frame encoding a 183-amino-acid polypeptide. The rat Coq7 amino acid sequence is 49% identical to that of yeast Coq7p and 58% identical to aC. eleganshomolog over a 152-aa region. Sequence homology searches fail to identify any other significant homologies. TheCoq7gene was mapped to mouse chromosome 7, 7.6 ± 3.6 cM proximal to the markerD7Mit7,by linkage analysis of an interspecific backcross. This region of chromosome 7 containingCoq7is part of a linkage group conserved between mouse chromosome 7 and human chromosome 11p15.