1. Histones and histone modifications
Craig L Peterson, Marc-André Laniel 
Current Biology 
Volume 14, Issue 14, Pages R546-R551 (July 2004)
DOI: /j.cub

2. Figure 1 Post-translational modifications of the core histones.
The colored shapes represent known post-translational modifications of the core histones. The histone tails can be methylated at lysines and arginines (green pentagons), phosphorylated at serines or threonines (yellow circles), ubiquitylated (blue stars) and acetylated (red triangles) at lysines.
Current Biology  , R546-R551DOI: ( /j.cub )