title: Metabolic regulation of beta-galactosidase synthesis in Escherichia coli. A test for constitutive ribosome synthesis.
abstract: The rate of differential synthesis of beta-galactosidase (alphalac) was measured in maximally induced cultures of Escherichia coli B/r with 0.01 M-inducer and 0.01 M-cyclic AMP. The value of alphalac decreases with growth rate (60% between 0.67 and 2.1 doublings/h) and after a nutritional shift-up. This decrease is presumed to reflect a decrease in the intracellular concentration of free active RNA polymerase after a shift-up, which implies that the increase in ribosome synthesis after a shift-up is due to an active induction of the ribosomal components.
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004790:Enzyme Induction; D004926:Escherichia coli / Q000201:enzymology* / Q000648:ultrastructure; D005696:Galactosidases / Q000096:biosynthesis*; D005947:Glucose / Q000378:metabolism; D007700:Kinetics; D012269:Ribosomal Proteins / Q000096:biosynthesis; D012270:Ribosomes / Q000201:enzymology / Q000378:metabolism*; D013386:Succinates / Q000378:metabolism
chemical_list: D000596:Amino Acids; D012269:Ribosomal Proteins; D013386:Succinates; D000242:Cyclic AMP; D012321:DNA-Directed RNA Polymerases; D005696:Galactosidases; D005947:Glucose