Histones undergo numerous post-translational modifications, including acetylation and methylation, at residues which are then probable docking sites for various chromatin remodelling complexes. Inhibitor of growth proteins (INGs) specifically bind to residues that have been thus modified. INGs carry a well-characterised C-terminal PHD-type zinc-finger domain, binding with lysine 4-tri-methylated histone H3 (H3K4me3), as well as this N-terminal domain that binds unmodified H3 tails. Although these two regions can bind histones independently, together they increase the apparent association of the ING for the H3 tail.

1: Critical Determinants for Chromatin Binding by Saccharomyces cerevisiae Yng1 Exist Outside of the PHD Finger. Chruscicki AT, Macdonald VE, Young BP, Loewen CJ, Howe LJ; Genetics. 2010; [Epub ahead of print] PMID:20351216