chromatin level;

(histone tails +vely charged, interact strongly w/ -vely charged phosphate group of s-p backbone of DNA)

histone acetylation > t/c

histone acetyltransferase(HATs) adds acetyl groups to lysine residues on histone tails >

removes +ve charge on histones, < histone affinity for DNA >

DNA coils < tightly around nucleosomes, chromatin decondenses -> euchromatin >

gene promoter > accessible to GTF & RNA pol

histone deacetylation < t/c

histone deacetylase(HDACs) removes acetyl groups to lysine residues on histone tails >

restore +ve charge on histones, > DNA affinity for nucleosome >

DNA coils > tightly around nucleosomes, chromatin condenses -> heterochromatin >

gene promoter < accessible to GTF & RNA pol

Review: H2 Biology 13 - Regulation of GE in eukaryotes