title: Identification of a glutaminyl-tRNA synthetase mutation Saccharomyces cerevisiae.
abstract: Saccharomyces cerevisiae glutaminyl-tRNA synthetase mutants were isolated through systematic screening of tight Gln- derivatives of a leaky glutamine auxotroph. These mutations define a single nuclear gene, GLN4. The gln4-1 mutation is specific for Gln-tRNA synthetase and shows a dosage effect in heterozygous diploids. The wild-type Gln-tRNA synthetase exhibits a Km for glutamine of 25 microM; the gln4-1 mutation increases this value 20-fold. These observations strongly suggest that GLN4 encodes the Gln-tRNA synthetase.
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics* / Q000378:metabolism; D005796:Genes; D005800:Genes, Fungal; D005971:Glutamates / Q000378:metabolism; D018698:Glutamic Acid; D005973:Glutamine / Q000378:metabolism; D007700:Kinetics; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*
chemical_list: D005971:Glutamates; D005973:Glutamine; D018698:Glutamic Acid; D000604:Amino Acyl-tRNA Synthetases; C020659:glutaminyl-tRNA synthetase