title: Requirement of protein and RNA synthesis for lambda repressor inactivation by tif-1: effects of chloramphenicol, neomycin and rifampicin.
abstract: The inactivation of lambda repressor was followed by the specific DNA binding assay during the course of lysogenic induction provoked by incubation at 42 degrees C of an E. coli tif-1 lysogenic strain. The presence of up to 400 microgram/ml chloramphenicol during the inducing treatment did not impair the loss of repressor binding activity, whilst concentrations of 200 microgram/ml neomycin and 100 microgram/ml rifampicin effectively inhibited the inactivation of lambda repressor. Residual protein synthesis in the presence of chloramphenicol, neomycin and rifampicin was 5%, 5% and 27% respectively of that observed in the drug-free control. This residual synthesis did not appear to involve amplification of the X-protein. These results suggest that tif-mediated inactivation of the lambda repressor requires the activation of some specific gene(s), the translation of which appears to be resistant to chloramphenicol.
mesh_terms: D001345:Autoradiography; D001426:Bacterial Proteins / Q000096:biosynthesis; D002701:Chloramphenicol / Q000494:pharmacology*; D003090:Coliphages / Q000235:genetics*; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics*; D005809:Genes, Regulator; D006358:Hot Temperature; D008242:Lysogeny / Q000187:drug effects*; D009355:Neomycin / Q000494:pharmacology*; D012329:RNA, Bacterial / Q000096:biosynthesis; D012293:Rifampin / Q000494:pharmacology*
chemical_list: D001426:Bacterial Proteins; D012329:RNA, Bacterial; D002701:Chloramphenicol; D009355:Neomycin; D012293:Rifampin