Reading and Interpreting the Histone Acylation Code

Decades of research has explored the epigenetic control of gene expression and the impact of histone post-translational modifications (PTMs), such as acetylation, on chromatin remodeling. Indeed, the writers, readers, and erasers of lysine acetylation are increasingly well understood. Recent studies have added crotonylation, butyrylation, and propionylation to the types of acylations by which histones are modified, and identified the YEATS protein domain as a critical reader of crotonylation. Now, Haitao Li, David Allis, and their colleagues expand the scope of protein domains capable of reading crotonyl-lysine (Kcr) to include double PHD finger (DPF) domains. Importantly, the mechanism through which these domains recognize Kcr is quite distinct from their recognition by the YEATS domain [1]. In this highlight, we discuss recognition of acylated histones by the bromodomain (BRD), the YEATS domain, and PHD fingers. We contrast the structural basis for their recognition of histones modified by acetylation and more recently discovered histone crotonylation [2–6]. Roles of histone acylation