Intrinsic protein disorder, amino acid composition, and histone terminal domains

Core and linker histones are the most abundant protein components of chromatin. Even though they lack intrinsic structure, the N- terminal "tail" domains (NTDs) of the core histones and the C- terminal tail domain (CTD) of linker histones bind to many different macromolecular partners while functioning in chromatin. Here we discuss the underlying physicochemical basis for how the histone terminal domains can be disordered and yet specifically recognize and interact with different macromolecules. The relationship between intrinsic disorder and amino acid composition is emphasized. We also discuss the potential structural consequences of acetylation and methylation of lysine residues embedded in intrinsically disordered histone tail domains.