MECP2 binds the SIN3A co-repressor complex. This interaction involves the transcriptional repressor domain of MECP2 and the amino-terminal part of the HDAC-interaction domain (HID) of SIN3A. HDAC1 and HDAC2 are part of the SIN3A co-repressor complex that co-immunoprecipitates with MECP2. Presence of other components of the SIN3A co-repressor complex has not been tested (Nan et al. 1998). MECP2 is not an obligate component of the SIN3A corepressor complex (Klose et al. 2004).