BIO370Y5 Lecture Notes - Lecture 12: Repressor, Isomerase, Pyruvic Acid
Document Summary
February 22, 2016: compound regulation of the lac operon (catabolite repression) Glucose is the number one nutrient source (if there"s other sugars, bacteria use glucose up first) Catabolite repression: when a catabolite (waste product of glucose) turns off the expression of certain genes. Glucose goes low then bacteria make cyclic adenosine 3", 5"- monophosphate (camp) Glucose goes down = camp goes up. Did a mutant screen with starved sugars and saw which mutants made camp when glucose was not there: basically found that camp needed to form complex with cap (catabolite activator protein) The whole complex is what bends proteins and activate transcription cap directly contants the. C-terminal domain of alpha subunit of rna pol. To fully active lac operon you need no glucose and lots of lactose to bind to repressor protein. Why do we care if it bends or does not: because that"s where the protein unwinds, arabinose operon.
