09BIS1012013TransciptLect9-1

The free subunit forms a new holoenzyme e with

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: harged DNA. However, it is the interaction between the σ subunit and the promoter sequence that enables RNAP to recognize and transcribe genes. The steps in initiation are as follows: RNAP binds the promoter sequence without strand separation (closed complex), DNA strands separate to form an open complex in the promoter The template strand is selected by β subunit, H bonding between complementary dexoynucleotides and ribonucleotides, A phosphodiester bond forms between the first and second ribonucleotide, RNAP begins moving in the 5' to 3' direction down the gene After 5 to 8 bases, the σ subunit dissociates from the RNAP leaving the core polymerase (E) to transcribe the DNA. The free σ subunit forms a new holoenzyme (Eσ) with another core polymerase. Eσ + DNA KB EσDNAclosed + Mg2+ EσDNAopen + NTP Ki K2 EσDNAopen EDNA + RNA + σ BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez ©2013 BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez 14 RNAP Promoter Binding http://bioweb.wku.edu/courses/biol22000/18TranscInitProk/default.html BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez ©2013 BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez 15 Initiation of Transcription Elongation Nucleotide Site (ENS) Primer Terminus Site (PTS) BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez ©2013 BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez 16 Transcription (Movie) Transcription Transcription Initiaiton Complex BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez ©2013 BIS101­001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez 17 Promoter Structure and Function Promoters were first defined genetically by Jacob and Monod as cisPromoters cis acting mutations that mapped to th...
View Full Document

This note was uploaded on 02/12/2014 for the course BIS 101 taught by Professor Simonchan during the Spring '08 term at UC Davis.

Ask a homework question - tutors are online