Assuntos
Citoplasma/genética , Mitocôndrias/genética , Fatores de Iniciação de Peptídeos/genética , Biossíntese de Proteínas , Proteínas de Ligação a RNA/genética , Ribonucleoproteínas Nucleares Pequenas , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Fator de Iniciação 4A em Eucariotos , Proteínas Fúngicas/genética , Fatores de Terminação de Peptídeos/genética , Proteínas Ribossômicas/genéticaRESUMO
We have cloned and sequenced the GDS1 gene located on the right arm of chromosome XV of Saccharomyces cerevisiae. The gene codes for a 522 amino acid serine-rich protein with no obvious homology to proteins in the database. GDS1 gene was isolated as the multicopy suppressor of the glycerol-deficient phenotype caused by the nam9-1 mutation in the yeast nuclear gene encoding the mitochondrial ribosomal protein homologous to S4 proteins from various organisms. Disruption-deletion of the GDS1 open reading frame leads to a partial impairment of growth on medium containing glycerol as the carbon source, indicating mitochondrial function of the gene product.
Assuntos
Genes Fúngicos , Saccharomyces cerevisiae/genética , Sequência de Aminoácidos , Sequência de Bases , Mapeamento Cromossômico , Cromossomos Fúngicos/genética , Clonagem Molecular , DNA Fúngico/genética , Proteínas Fúngicas/genética , Deleção de Genes , Mitocôndrias/metabolismo , Dados de Sequência Molecular , Fenótipo , Saccharomyces cerevisiae/metabolismoRESUMO
The nuclear gene NAM9 from Saccharomyces cerevisiae (Sc) codes for a protein which, on the basis of sequence homology, was previously postulated to be a mitochondrial (mt) equivalent of the Escherichia coli (Ec) S4 ribosomal protein (r-protein) [Boguta et al., Mol. Cell. Biol. 12 (1992) 402-412]. The mt-r character of the NAM9 product is now confirmed by cross-reaction with the antisera for the Sc mt r-proteins. The NAM9-1 mutation, characterized previously as the nuclear suppressor of some ochre mt mit- mutants, is found to be a single nucleotide substitution changing Ser82 to Leu within the part of NAM9 corresponding to the S4 region involved in interaction with the 16S rRNA. This indicates that the mechanism of NAM9-1 suppression could be analogous to the suppression due to ram (ribosomal ambiguity) mutations in the Ec structural gene encoding r-protein S4. The NAM9-1 mutation leads also to defect in respiratory growth in the background of the wild-type mit+ genome.