title: Indolmycin-mediated inhibition and stimulation of transcription at the trp promoter of Escherichia coli.
abstract: Escherichia coli cells harboring a non-attenuated trp-lac operon fusion were used to evaluate the effects of indolmycin on the initiation of transcription at the trp promoter. Indolmycin caused repression in trpR+ strains and in trpR deletion mutants, although higher effector concentrations were required in the latter situation. Plasmid-mediated elevation in tryptophanyl-tRNA synthetase reversed the inhibitory effect of indolmycin. Indolmycin did not facilitate the binding of purified Trp repressor protein to trp operator DNA.
mesh_terms: D001426:Bacterial Proteins; D004269:DNA, Bacterial / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D007211:Indoles / Q000494:pharmacology*; D009154:Mutation; D009876:Operon; D012097:Repressor Proteins / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*; D014364:Tryptophan / Q000096:biosynthesis*; D014369:Tryptophan-tRNA Ligase / Q000378:metabolism; D029968:Escherichia coli Proteins
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D007211:Indoles; D012097:Repressor Proteins; D014364:Tryptophan; D014369:Tryptophan-tRNA Ligase; C027190:TRPR protein, E coli; D029968:Escherichia coli Proteins; C001447:indolmycin