Global profiling of crotonylation on non-histone proteins

Dear Editor, Lysine crotonylation is a posttranslational modifi- cation （PTM） of histone proteins originally identified by Tan et al. [1]. This novel evolutionarily conserved histone modification was identified on 28 lysine sites on various histones [1]. Lysine crotonylation occurs primar- ily on the ε-amino group of lysine, but its planar orien- tation and four-carbon length distinguish it from lysine acetylation. Histone crotonylation specifically labels the enhancers and transcription starting sites of active genes in both the human somatic cell genome and the murine male germ cell genome. Histone crotonylation, like acetylation.