title: Mutations in the tryptophanyl-transfer ribonucleic acid ligase of E. coli causing temperature-sensitivity for growth.
abstract: Strains of Escherichia coli K-12 with altered tryptophanyl-tRNA ligases, conferring temperature-sensitivity for growth, have been isolated as spontaneous one-step mutants. The mutated enzymes differ markedly in activity from the wildtype, even at the permissive temperature. When assayed at the non-permissive temperature, the mutant enzymes are completely inactive. In one of the mutant strains, growth can be completely inhibited by addition of L-phenylalanine or L-tyrosine to the medium.
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics*; D003470:Culture Media; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification; D006358:Hot Temperature; D009154:Mutation; D010641:Phenotype; D010649:Phenylalanine / Q000494:pharmacology; D014369:Tryptophan-tRNA Ligase / Q000235:genetics*; D014443:Tyrosine / Q000494:pharmacology
chemical_list: D003470:Culture Media; D014443:Tyrosine; D010649:Phenylalanine; D000604:Amino Acyl-tRNA Synthetases; D014369:Tryptophan-tRNA Ligase