Dual function of a new nuclear gene for oxidative phosphorylation and vegetative growth in yeast.
A new gene essential for cell viability and indispensable for the biogenesis of a functional respiratory chain in Saccharomyces cerevisiae was isolated by complementing a temperature-sensitive mutant. This conditional nuclear mutation selectively affects oxidative phosphorylation at restrictive temperatures. At the molecular level a severe and complex defect inside mitochondria is observed, with drastically reduced levels of mitochondrial transcripts. Surprisingly a null mutation in this nuclear gene in a haploid yeast strain leads to cell death. Spores containing a disrupted copy of the gene exhibit a severe growth defect and cell division stops irreversibly after 3 to 4 days. It is shown that the null and conditional mutants are indeed allelic. This finding demonstrates a dual function of the gene product in oxidative phosphorylation and vegetative growth. The putative protein product, as deduced from the sequence of the relevant reading frame is characterized by a low molecular weight of approximately 14 kDa, a high content of charged amino acids and a very low codon bias index. A transcript of low abundance and with a length of about 600 nucleotides can be assigned to this gene.
Lisowsky
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Botanisches Institut, Heinrich-Heine Universität Düsseldorf, FRG.
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal / Q000502:physiology; D005800:Genes, Fungal / Q000235:genetics*; D005804:Genes, Lethal / Q000235:genetics; D024101:Mitochondrial Proteins; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010085:Oxidative Phosphorylation; D050862:Oxidoreductases Acting on Sulfur Group Donors; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D013696:Temperature
D005656:Fungal Proteins; D024101:Mitochondrial Proteins; D029701:Saccharomyces cerevisiae Proteins; D050862:Oxidoreductases Acting on Sulfur Group Donors; C073790:ERV1 protein, S cerevisiae