| CHD 4 ( also called Mi 2beta ) is a component of a histone deacetylase 2 ( HDAC 2 ) containing complex , the nucleosome remodeling and deacetylating ( NRD ) complex . ^^^ Molecular association between ATR and two components of the nucleosome remodeling and deacetylating complex , HDAC 2 and CHD 4 . ^^^ Endogenous ATR , CHD 4 , and HDAC 2 are shown to coimmunoprecipitate , and ATR and HDAC 2 coelute through two biochemical purification steps . ^^^ ATR ' s association with CHD 4 and HDAC 2 suggests that there may be a linkage between ATR ' s role in mediating checkpoints induced by DNA damage and chromatin modulation via remodeling and deacetylation . . ^^^ |