BIO230H1 Lecture Notes - Lecture 3: Lambda Phage, Synthetic Biology, Repressor
BIO230H1 verified notes
3/27View all
Document Summary
Prokaryotic transcriptional regulation continued: recap of prokaryotic gene regulation, bacteriophage lamba, synthetic biology, transcription attenuation. Competition between rna polymerase and repressor protein for promoter binding. Activator protein recruits rna polymerase to the promoter to activate transcription. Repressor contains a helix-turn-helix dna binding motif. Binds in major grooves of dna double helix. Tryptophan binding induces conformational change, fits in major groove. Gene regulatory elements are typically close to the transcriptional start. Very far away from genes they control. But folds in dna layer proteins such as. Positive and negative regulatory mechanism work together to regulate the lifestyles of bacteriophage lambda. Lambda will divide with the bacteria dna. Replicates within bacteria, lysis bacteria, and enters the environment. Dna is replicated, packaged, new bacteriophage released by host. Virus hitches along for ride along bacterial genome. Operator found in the middle, controls both genes. Most bacteriophage dna not transcribed, will be replicated later. Two gene regulatory proteins are responsible for initiating this switch.
