CHD6, CHD7, CHD8, CHD9 subfamily

CHD6, CHD7, CHD8, CHD9 subfamily CHD6, CHD7, CHD8 and CHD9 make up subfamily III, based on their orthology to the founding member in Drosophila, Kismet (Tamkun et al, 1992, Daubresse et al, 1999). Like subfamily I and II proteins, subfamily III proteins have tandem N-terminal chromodomains and a SNF2 ATPase domain, but also have additional C-terminal motifs including a Brahma-Kismet (BRK) domain, a SANT motif, and a DNA-binding region (reviewed in Marfella and Imbalzano, 2007; Alendar and Berns, 2021). The function of the BRK domain, so named because of its identification in the Drosophila Brahma and Kismet proteins, is not elucidated but it may play a role in binding CTCF (Allen et al, 2007; Ishihara et al, 2006). Like other CHD proteins, subfamily III is implicated in regulation of transcription, proliferation and repair of DNA damage (reviewed in Alendar and Berns, 2021). Although CHD6-9 are 50-54% identical, they appear to have distinct biochemical characteristics and to play non-redundant biological roles (Manning and Yusufzai, 2017; reviewed in Mills et al, 2017).