BIO 362 Lecture Notes - Lecture 18: Ribosomal Rna, Glycosylation, Backtracking
Document Summary
Transcription initiation is key step to where regulation occurs. Normal transcription cycle- rna poly binds sigma and dna promoter close config turns to open template strand into active site transcribe rna extended while dsdna is being pulled into active site. Template dna reanneals with coding dna and exits out of rna poly; sigma factor recognizes promoter opens up abortive transcription elongation (many cases sigma is released once rna poly in this mode) In previous experiment, made changes in dna seq of promoter; can also make mutation in sigma factor to destabilize it (reduce affinity for promoter) less abortive transcription, more full-length transcription promoter escape is rate-limiting step. ***rna poly in order to synthesize rna, must be bound to promoter at -35 and -10 aborts that transcript and starts from same promoter. (cid:862)tra(cid:374)sie(cid:374)t e(cid:454)cursio(cid:374)(cid:863)- rna poly moves a little forward and then goes back as a total, which releases transcript it makes (no appealing)
