Devoided of intrinsic deacetylase activity, promotes the deacetylation of lysine residues on the N-terminal part of the core histones (H2A, H2B, H3 and H4) by recruiting other histone deacetylases. Histone deacetylation gives a tag for epigenetic repression and plays an important role in transcriptional regulation, cell cycle progression and developmental events. Represses MEF2-dependent transcription (By similarity). H2O + N(6)-acetyl-L-lysyl-[histone] = acetate + L-lysyl-[histone] Homodimer. Interacts with mef2 (By similarity). Belongs to the histone deacetylase family. HD type 2 subfamily.