Biochemistry 3382A Study Guide - Final Guide: Catabolite Repression, Transcription Factor Ii D, Guanosine

• School: Western University
• Department: Biochemistry
• Course: Biochemistry 3382A
• Professor: David Litchfield

Document Summary

Binding: rna polymerase binds ( 2 " ) and reads along until it finds the -35 and. Pribnow box is near the 10, tataat consensus sequence good for unwinding due to weaker h bonds, rna poly binds unwound dna much much better. 35 region ttgaca is the binding region for the sigma subunit, the closer to consensus sequence, the better sigma binds and the higher the transcription efficiency. First nucleotide preferred in initiation site of rnap is atp or gtp. Elongation (without sigma the rnap is now the elongation enzyme) 20-50 nts per second, slower in gc regions, error rate one in 10,000. Gyrase introduces negative supercoiling ahead of rnap while topoisomerase releases the supercoiling behind it. Rho independent or intrinsic: hair pin loop (inverted gc rich repeat) with long stretch of (6-8 us makes rnap fall off) Operons (polycistrons) controlled by operators (can be upstream or downstream, inducer or repressor)