ISOLATION OF A CDNA-ENCODING THE HUMAN HOMOLOG OF COX17, A YEAST GENEESSENTIAL FOR MITOCHONDRIAL COPPER RECRUITMENT

The COX17 gene of Saccharomyces cerevisiae codes for a cytoplasmic pro tein essential for the expression of functional cytochrome oxidase. Th is protein has been implicated in targeting copper to mitochondria. To determine if Cox17p is present in mammalian cells, a yeast strain car rying a null mutation in COX17 was transformed with a human cDNA expre ssion library. All the respiratory competent clones obtained from the transformations carried a common cDNA sequence with a reading frame pr edicting a product homologous to yeast Cox17p. The cloning of a mammal ian COX17 homolog suggests that the encoded product is likely to funct ion in copper recruitment in eucaryotic cells in general. Its presence in humans provides a possible target for genetically inherited defici encies in cytochrome oxidase.