title: Escherichia coli mutant strain with altered expression of the tryptophan operon: ribonucleic acid synthesis in vitro.
abstract: Ribonucleic acid (RNA) synthesis has been studied in vitro with a partially purified preparation of RNA polymerase from a mutant strain of Escherichia coli with a reduced rate of accumulation of tryptophan RNA (P.H. Pouwels and H.J. Scholten, J. Bacteriol. 139:393-397, 1979). The incorporation of radioactive label into RNA with polymerase from mutant bacteria is considerably lower than that with the enzyme from wild-type bacteria. These results are explained by the presence in mutant bacteria, but not in wild-type bacteria, of a factor which suppresses the accumulation of RNA. Mutant bacteria contain a factor which renders RNA synthesis with mutant and wild-type RNA polymerase resistant to various inhibitors of RNA synthesis, e.g. rifampin, streptolydigin, and heparin. We conclude that in mutant bacteria a factor is modified which suppresses the accumulation of some RNA species and lowers the sensitivity of RNA polymerase to some transcription inhibitors.
mesh_terms: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D006493:Heparin / Q000494:pharmacology; D009154:Mutation; D009876:Operon; D012329:RNA, Bacterial / Q000096:biosynthesis*; D012293:Rifampin / Q000494:pharmacology; D014364:Tryptophan / Q000096:biosynthesis*
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D012329:RNA, Bacterial; D014364:Tryptophan; D006493:Heparin; D012321:DNA-Directed RNA Polymerases; D012293:Rifampin