Cloning and characterization of PET100, a gene required for the assembly of yeast cytochrome c oxidase.
The biogenesis of cytochrome c oxidase in Saccharomyces cerevisiae requires a protein encoded by the nuclear gene, PET100. Cells carrying a recessive mutation (pet100-1) in PET100 are respiratory deficient and have reduced levels of cytochrome c oxidase activity. The PET100 gene has been cloned by complementation of pet100-1, sequenced and disrupted. PET100 is located adjacent to the PDC2 gene on chromosome IV and contains an open reading frame of 333 base pairs. The PET100 protein contains a possible membrane-spanning segment and a putative mitochondrial import sequence at its NH2 terminus. A strain carrying a null mutation in PET100 lacks cytochrome c oxidase activity and assembled cytochromes a and a3, but the other respiratory chain carriers are present. The respiratory-deficient phenotype of this strain is not rescued by added hemin or heme A. These findings indicate that the mutation is specific for cytochrome c oxidase and does not affect the biosynthesis of heme A. In addition, mitochondria from the strain carrying a null mutation in PET100 contain each of the subunit polypeptides of cytochrome c oxidase. Together, these findings suggest that PET100p is not required for the synthesis or localization of cytochrome c oxidase subunits to mitochondria, but is required at a later step in their assembly into an active holoenzyme.
Church
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Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado 80309-0347, USA.
Chapon
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Poyton
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D000595:Amino Acid Sequence; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000235:genetics; D003576:Electron Transport Complex IV / Q000096:biosynthesis* / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics*; D005800:Genes, Fungal; D008928:Mitochondria / Q000201:enzymology; D018832:Molecular Chaperones; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics*; D010641:Phenotype; D017433:Protein Structure, Secondary; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins
D004271:DNA, Fungal; D005656:Fungal Proteins; D018832:Molecular Chaperones; D009687:Nuclear Proteins; C100954:PET100 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D003576:Electron Transport Complex IV