Answer:
Lysine
Explanation:
lysine residues on the histone tails of the octamer cn be activated by both acetylation and methylation patterns to influence accessibility or silencing of the genes respectiviely. for example, acetylation of H3K27 (histone 3 lysine residue 27) brings about a region of active chromatin allowing access to transcription activity while its trimethylation will cause silencing of the associated gene at that particular area (no expression of that gene)
