These tails can be posttranslationally modified, and major forms of mammalian acetylation and methylation modifications on lysine residues on each tail are highlighted. The molecules are drawn approximately proportional to the protein, although the number of residues shown is not meant to reflect the exact size of the N-terminal tails. This image was published in Sun HS, Kennedy PJ, Nestler EJ. Epigenetics of the depressed brain: role of histone acetylation and methylation. Neuropsypharmacology Rev. 2013:38:124-137. The author retains the copyright.