BIOL 2905 Chapter Notes - Chapter 4: Lysine, Euchromatin, Heterochromatin
13 Oct 2017
School
Department
Course
Professor
Document Summary
Euchromatin relative to heterochromatin: in euchromatin, the machinery has more access to dna. Thus more gene expression & house keeping genes are found here things that are on constituency: transcriptionally active dna is more sensitive to degrading enzymes- readily cut. Chromatin remodelling: complexes destabalize chromatin structure to all access to promoters, remodelling comples move nucleosomes & reposition them along dna, it gives rna polymerase temporary access to promoter region of dna. Histone modifications: parts of histones stick out to allow for modification- histone tails get modified, a(cid:272)etyl groups (cid:272)a(cid:374) (cid:271)e added to lysi(cid:374)e"s to allow (cid:373)odifi(cid:272)atio(cid:374, hats added acetyl groups to specific lysine to tails of histones. It decreases the positive charge of tail/histones which disrupts histones interaction with. Results in a more loosened & accessible dna: process of acetylation is reversible. Hats add acyl groups ; hdats remove acyl groups: hdats are recruits by prepressors to prevents transcription of gene.
