MBD5 and MBD6 are two members of the methyl-CpG-binding domain (MBD) family. They do not bind methylated DNA [], but instead they interact with the PR-DUB Polycomb protein complex in a mutually exclusive manner. They may share a function through their interaction with PR-DUB. MBD6, but not MBD5, is recruited to sites of DNA damage []. MBD5 is highly expressed in oocytes [].