title: Mechanism of activation of catabolite-sensitive genes: a positive control system.
abstract: Catabolite repression is defined as the inhibition of enzyme induction by glucose or related substances. In the bacterium E. coli, the effect of glucose appears to be due to a lowering of the cyclic AMP level. A DNA-directed cell-free system for beta-galactosidase synthesis has served as a model system for studying the mechanism of action of cyclic AMP. Previously, it was reported that in this system cyclic AMP is required for normal initiation of mRNA synthesis. A protein factor which acts in conjunction with the cyclic AMP has been partially purified. This protein factor has a high affinity for cyclic AMP. These and other results presented herein lead us to the conclusion that cyclic AMP and a protein factor called the catabolite gene activator protein are part of a positive control system for activating catabolite-sensitive genes.
mesh_terms: D000227:Adenine Nucleotides / Q000502:physiology*; D002474:Cell-Free System; D000242:Cyclic AMP / Q000502:physiology; D004790:Enzyme Induction / Q000187:drug effects; D004926:Escherichia coli / Q000378:metabolism; D005696:Galactosidases / Q000096:biosynthesis; D005796:Genes; D005947:Glucose / Q000494:pharmacology; D008660:Metabolism; D008967:Molecular Biology; D012333:RNA, Messenger / Q000096:biosynthesis; D014316:Tritium
chemical_list: D000227:Adenine Nucleotides; D012333:RNA, Messenger; D014316:Tritium; D000242:Cyclic AMP; D005696:Galactosidases; D005947:Glucose