title: Direct selection and analysis of mutational events which diminish the level of expression of the trp operon.
abstract: A new procedure was devised for selecting, from lac+ galE strains of Escherichia coli, mutants resistant to galactoside-induced lysis. When applied to trp-lac fusions, our method yields down mutations in the trp promoter.
mesh_terms: D001433:Bacteriolysis; D004926:Escherichia coli / Q000235:genetics*; D005697:Galactosides / Q000494:pharmacology; D007763:Lac Operon; D009154:Mutation; D009876:Operon; D011995:Recombination, Genetic; D014364:Tryptophan / Q000096:biosynthesis*
chemical_list: D005697:Galactosides; D014364:Tryptophan