title: In vivo regulation of chromosomal beta-lactamase in Escherichia coli.
abstract: Chromosomal beta-lactamase, a periplasmic enzyme of Escherichia coli, was studied with respect to its regulation in vivo. Both the activity and the amount of beta-lactamase increased with growth rate. During a nutritional shift-down, chromosomal beta-lactamase activity followed stable ribonucleic acid accumulation. After a nutritional shift-up the differential rate of beta-lactamase synthesis did not increase immediately (like stable ribonucleic acid), but did increase after a lag period of 30 min. To determine whether beta-lactamase was under stringent control, strains carrying a temperature-sensitive valyl-transfer ribonucleic acid synthetase and differing only in the allelic state of the relA gene were shifted from a permissive to a semipermissive temperature. No influence by the relA gene product was found on beta-lactamase synthesis. The regulation of this periplasmic enzyme is discussed in relation to that of some components of the translational apparatus.
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis; D002876:Chromosomes, Bacterial; D003470:Culture Media; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D005809:Genes, Regulator; D009154:Mutation; D012329:RNA, Bacterial / Q000096:biosynthesis; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D012329:RNA, Bacterial; D001618:beta-Lactamases