Responsible for the deacetylation of lysine residues on the N-terminal part of the core histones (H2A; H2B; H3 and H4). Histone deacetylation gives a tag for epigenetic repression and plays an important role in transcriptional regulation; cell cycle progression and developmental events. Histone deacetylases act via the formation of large multiprotein complexes. Required for proper positioning of nucleosomes at heterochromatic loci and for transcriptional gene silencing (TGS) function of the Snf2/Hdac- containing repressor complex (SHREC). {ECO:0000269|PubMed:17289569}.