Histone Acetylation

Histone acetylation is a post-translational modification involving the addition of an acetyl group (COCH₃) from acetyl coenzyme A with the use of enzymes called histone acetyltransferases. These enzymes catalayse the addition of an acetyl group on to lysine residues in areas which are usually promoter regions, such as H3 and H4. As lysine is postively charged and DNA is negatively charged they bind together keeping the structure compact, however with the addition of a positvely charged acetylation the structure becomes less compact thus revealing promoter regions for transcription to occur. Acetyl groups can be removed from lysine residues in a hydrolytic process using histone deactylases. The acetylation of histones is involved in many cellular processes.