title: RNA polymerase interaction at the promoter--operator region of the tryptophan operon of Escherichia coli and Salmonella typhimurium.
mesh_terms: D001483:Base Sequence; D004269:DNA, Bacterial; D012321:DNA-Directed RNA Polymerases; D004586:Electrophoresis; D004926:Escherichia coli / Q000235:genetics*; D009876:Operon; D012333:RNA, Messenger; D012486:Salmonella typhimurium / Q000235:genetics*; D014158:Transcription, Genetic; D014364:Tryptophan
chemical_list: D004269:DNA, Bacterial; D012333:RNA, Messenger; D014364:Tryptophan; D012321:DNA-Directed RNA Polymerases