Cloning and characterization of the yeast methionyl-tRNA synthetase mutation mes1.
The chromosomal mes 1 mutation appears to elevate the Km of methionine for yeast methionyl-tRNA synthetase. The mutation was cloned on a multicopy plasmid by gap repair of a plasmid bearing the wild type MES1 gene for a fragment corresponding to the mes 1 mutation. DNA sequencing established that the mutation consists of a single conversion of guanine into adenine which results in the replacement of a glycine by an aspartic acid at position 502. This causes the enzyme to be labile and inactive in vitro and to show a requirement for high concentrations of methionine in vivo. The mutation is in the COOH-terminal domain of the mononucleotide binding fold of the yeast enzyme and suggests participation of this region in the binding of the amino acid residue.
Chatton
B
B
Institut de Biologie Moleculaire et Cellulaire du Centre National de la Recherche Scientifique, Strasbourg, France.
Winsor
B
B
Boulanger
Y
Y
Fasiolo
F
F
D000483:Alleles; D000595:Amino Acid Sequence; D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics*; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D005796:Genes; D005800:Genes, Fungal; D008718:Methionine-tRNA Ligase / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*
D000604:Amino Acyl-tRNA Synthetases; D008718:Methionine-tRNA Ligase