vsb.orgMethylation been discovered on a spread of lysine residues in varied histones: K4 (using the single-letter amino-acid code for lysine), K9, K27, K36 and K79 in histone H3, K20 in histone H4, K59 within the globular area of histone H4 2 and K26 of histone H1B 3 Several proteins responsible for the methylation of particular residues have been characterized, and all but considered one of these contains a SET domain