7/24/2019 l 16 Transcription

1/7

L16 TranscriptionRecognition, Initiation, Elongation and Terminatio

7/24/2019 l 16 Transcription

2/7

Stages of Transcription

Promoter Recognition

Chain Initiation

Chain Elongation

Chain Termination

7/24/2019 l 16 Transcription

3/7

Transcription: promoter recogni

Transcription factors bind to promoter seqenceecrit R!" pol#merase$

Transcription factors that are reqired at e%er# psite for R!" pol#merase

http://www.ncbi.nlm.nih.gov/books/bv.fcgi?call=bv.View..ShowSection&rid=dbio.figgrp.752http://www.ncbi.nlm.nih.gov/books/bv.fcgi?call=bv.View..ShowSection&rid=dbio.figgrp.752http://www.ncbi.nlm.nih.gov/books/bv.fcgi?call=bv.View..ShowSection&rid=dbio.figgrp.752http://www.ncbi.nlm.nih.gov/books/bv.fcgi?call=bv.View..ShowSection&rid=dbio.figgrp.752

7/24/2019 l 16 Transcription

4/7

Promoter recognition: promoter seqences

Promoter seqences %ar# considerabl#$ R!" pol#merase binds to di&erent promoters 'it

di&erent strengths( binding strength relates to thof gene e)pression

7/24/2019 l 16 Transcription

5/7

Transcription: chain initiation

Chain initiation: R!" pol#merase locall# denatres the *!"$

The +rst base of the ne' R!" strand is placedcomplementar# to the 1 site$

R!" pol#merase does not reqire a primer$

The +rst - or . bases of the transcript are lin/edTranscription factors are released, and the pol#mlea%es the promoter region$

http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mcb.figgrp.2615http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mcb.figgrp.2615

7/24/2019 l 16 Transcription

6/7

Transcription: chain elongation

Chainelongation: R!" pol#merase mo%es along the transcribed or

template *!" strand$

The ne' R!" molecle 0primar# transcript formshort R!"2*!" h#brid molecle 'ith the *!" te

http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=stryer.figgrp.3968http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=stryer.figgrp.3968http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=stryer.figgrp.3968http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=stryer.figgrp.3968

7/24/2019 l 16 Transcription

7/7

Transcription: chain termination

3ost /no'n abot bacterial chain terminationTermination is signaled b# a seqence that can f

hairpin loop$

The pol#merase and the ne' R!" molecle are pon formation of the loop$

$

http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=cooper.figgrp.970http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=cooper.figgrp.970