A class of proteins containing chromodomains that are involved in binding to histones. Chromobox protein homologue 1 (CBX1, heterochromatin protein 1 homologue β, 185 aa) binds histone H3 tails that are methylated at Lys-9; chromobox protein homologue 2 ( CBX2, 532 aa) is a component of the polycomb repressive complex-1 (PRC1). Chromobox protein homologue 3 (CBX3, 183 aa) also binds methylated histone H3 and is involved in the formation of a functional kinetochore through interaction with MIS12 complex proteins. Chromobox protein homologue 4 (CBX4, E3 SUMO-protein ligase, 558 aa) facilitates SUMO1 conjugation by UBE2I and is a component of PRC1. At least four other chromobox protein homologues are known.
Subjects: Medicine and Health.