chromodomain of heterochromatin protein 1 homolog beta
CHRomatin Organization Modifier (chromo) domain of heterochromatin protein 1 homolog beta (also known as HP1beta, CBX1, and chromobox 1), and related proteins. HP1beta is a highly conserved non-histone protein, which is a member of the heterochromatin protein family, and is enriched in the heterochromatin and associated with centromeres. HP1 has two conserved protein-protein interaction domains, a single N-terminal chromodomain (CD) which can bind to histone proteins via methylated lysine residues, and a related C-terminal chromo shadow domain (CSD) which is responsible for the homodimerization and interaction with a number of chromatin-associated non-histone proteins; a flexible hinge region separates the CD and CSD and may bind nucleic acid. HP1 is a highly conserved non-histone chromosomal protein that is evolutionarily conserved from fission yeast to plants and animals. There are three human homologs of HP1 proteins: HP1alpha (also known as Cbx5), HP1beta, and HP1gamma (also known as Cbx3).