title: [Stringent control of relA gene transcription in cells of Escherichia coli].
abstract: Regulation of E. coli K12 relA gene transcription was studied. The rate of relA-RNA synthesis was measured by RNA-DNA-hybridization technique using cloned fragment of relA gene. Under seryl-tRNA deficiency the rate of relA-RNA synthesis was reduced six times in the strain CP78 (relA+) and only two times in its' relA-variant CP79. Chloramphenicol addition stimulated the rate of relA-RNA synthesis in starved relA+ cells. It was concluded that relA gene transcription is under "stringent control". The rate of relA-RNA synthesis increases proportionally with bacteria growth rate. Grown in glucose-minimal media strain with several copies of relA gene exhibits elevated ppGpp level (50 pmol/A450) and reduced rate of relA-RNA synthesis per one copy of relA gene. Thus, relA gene transcription is under negative regulation of ppGpp.
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D002701:Chloramphenicol / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D005796:Genes / Q000187:drug effects; D005798:Genes, Bacterial / Q000187:drug effects; D007700:Kinetics; D012329:RNA, Bacterial / Q000235:genetics; D012346:RNA, Transfer, Amino Acyl / Q000235:genetics; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012346:RNA, Transfer, Amino Acyl; D002701:Chloramphenicol
vernacular_title: "Strogiĭ" kontrol' transkriptsii gena relA v kletkakh Escherichia coli.