Chromatin Modification 2

Chromatin Modification 2 - Chromatin Modification I. R NAP,...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Chromatin Modification I. RNAP, TFII, and mediators are unable to assemble on packaged chromatin a. When chromatin is condensed, essentially the gene is “off” b. Histone tails are more accessible when extended than when they are condensed c. Activators help accelerate the rate of transcription initiation, and also attract general TFs, mediator, and RNAP II at the promoter i. The mediator provides an extended contact area for gene regulatory proteins d. Gene regulatory proteins (TF factors) initiate chromatin opening II. Eukaryotic gene activator proteins modify local chromatin structure a. In general, transcription can be repressed when a promoter and flanking sequences are wound up in a nucleosome and are inaccessible to RNA polymerase b. gene activator proteins can bind directly to DNA that is packaged in unmodified chromatin and subsequently promotes transcription initiation by changing the chromatin structure of regulatory sequences & promoters c. local chromatin structure is altered with the help of: i. histone modification enzymes ii. ATP-dependent chromatin remodeling complexes (nucleosomal sliding, removal, replacement) iii. Histone chaperones
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/12/2010 for the course MCDB 165B taught by Professor Nakano during the Winter '10 term at UCLA.

Page1 / 6

Chromatin Modification 2 - Chromatin Modification I. R NAP,...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online