title: Inhibitor-induced shift-downs in Escherichia coli.
abstract: A shift-down response in Escherichia coli cells has been brought about by moderate concentrations of azide or cyanide. Early events of the response included a preferential inhibition of ribonucleic acid relative to deoxyribonucleic acid synthesis, a degradation of polyribosomes, and an inhibition of protein synthesis followed by a transient relief. These changes were entirely comparable to those observed with nutrient-induced shift-downs. The influences of various nutrient supplements on an azide shift-down were examined, and methionine was found to relieve effectively the inhibition of ribonucleic acid synthesis in some strains of cells.
mesh_terms: D000596:Amino Acids / Q000494:pharmacology; D001386:Azides / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000096:biosynthesis; D002151:Calorimetry; D002247:Carbon Isotopes; D003470:Culture Media; D003486:Cyanides / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000096:biosynthesis*; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D007930:Leucine / Q000494:pharmacology; D009705:Nucleosides / Q000494:pharmacology; D012329:RNA, Bacterial / Q000096:biosynthesis*; D013941:Thymine / Q000494:pharmacology; D014529:Uridine / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D001386:Azides; D001426:Bacterial Proteins; D002247:Carbon Isotopes; D003470:Culture Media; D003486:Cyanides; D004269:DNA, Bacterial; D009705:Nucleosides; D012329:RNA, Bacterial; D007930:Leucine; D013941:Thymine; D014529:Uridine