Biochemistry 2280A Study Guide - Quiz Guide: Histone H2A, Nucleosome, Chromatin

• School: Western University
• Department: Biochemistry
• Course: Biochemistry 2280A
• Professor: Mclachlin

Document Summary

Molecular biology of dna: to fit into cells, dna must wind around proteins called histones to form chromatin, chromatin -> condense dna within cellular nucleus. >>limits access of rna polymerase to dna template -> preventing transcription & expression of genes: chromatin remodelling -> the opening of chromatin enabling dna transcription, chromatin remodellers. >>similar sequence -> dna translocation proteins -> viruses & bacteria. >domains & proteins attached -> nucleosome selection & regulation of atpase. > directional translocases -> directional pumping of dna: histone modification state determines appropriateness of substrate -> remodeler complex, mechanism of restructuring nucleosomes: >>binds -> 40 base pairs -> dna within nucleosome. >>exposes dna -> regulatory factors: nucleosome -> role -> directing transcriptional elements. >> 8 histone proteins -> 2 each of h2a, h2b, h3 & h4. H2a z variant -> near inactive gene promoters. >exchanged -> chromatin remodelling complex swr1 -> catalyses. Atp dependent exchange of h2a for h2a z: histone -> tail -> 2 ends.