Methylation of lysine 9 in histone H3 directs alternative modes of highly dynamic interaction of heterochromatin protein hHP1β with the nucleosome.

ABSTRACT: Binding of heterochromatin protein 1 (HP1) to the histone H3 lysine 9 trimethylation (H3K9me3) mark is a hallmark of establishment and maintenance of heterochromatin. Although genetic and cell biological aspects have been elucidated, the molecular details of HP1 binding to H3K9me3 nucleosomes are unknown. Using a combination of NMR spectroscopy and biophysical measurements on fully defined recombinant experimental systems, we demonstrate that H3K9me3 works as an on/off switch regulating distinct binding modes of hHP1β to the nucleosome. The methyl-mark determines a highly flexible and very dynamic interaction of the chromodomain of hHP1β with the H3-tail. There are no other constraints of interaction or additional multimerization interfaces. In contrast, in the absence of methylation, the

SUBMITTER: Munari F 

PROVIDER: S-EPMC3460472 | biostudies-literature | 2012 Sep

REPOSITORIES: biostudies-literature