BIOLOGY 207 Lecture Notes - Lecture 25: Ribosomal Rna, Guanosine Pentaphosphate, Repressor
Document Summary
The key to inducer exclusion, is that a component of the glucose transport system, will bind to and inhibit lac permease. Glucose moves from this phosphotransferase system (phosphotransferase system allows glucose to move down a concentration gradient because it gets converted from glucose to glucose-6-phosphate through phosphorylation) When glucose is present this transfer system can add phosphates to glucose and this system itself is left without phosphates. It"s this unphosphorylated enzyme that interacts with lacy and inhibits lacy activity. All the phosphates coming off including 2a. Now enzyme 2a and its phosphorylated form can no longer interact with lacy. Lacy can now import lactose into the self, and now the lac operon can be induced. Besides the lac operon model, bacteria have many different ways to regulate gene expression. Coupling of transcription & translation can also regulate gene expression by attenuation .
