Histone deacetylases and histone-like deacetylases, classII
Class II histone deacetylases are Zn-dependent enzymes that catalyze hydrolysis of N(6)-acetyl-lysine residues of histones (EC 3.5.1.98) and possibly other proteins to yield deacetylated histones/other proteins. This group includes animal HDAC4,5,6,7,8,9,10, fungal HOS3 and HDA1, plant HDA5 and HDA15 as well as other eukaryotes, archaeal and bacterial histone-like deacetylases. Eukaryotic deacetylases mostly use histones (H2, H3, H4) as substrates for deacetylation; however, non-histone substrates are known (for example, tubulin). Substrates for prokaryotic histone-like deacetylases are not known. Histone acetylation/deacetylation process is important for mediation of transcriptional regulation of many genes. Histone deacetylases usually act via association with DNA binding proteins to target specific chromatin regions. Interaction partners of class II deacetylases include 14-3-3 proteins, MEF2 family of transcriptional factors, CtBP, calmodulin (CaM), SMRT, N-CoR, BCL6, HP1alpha and SUMO. Histone deacetylases play a role in the regulation of cell cycle, cell differentiation and survival. Class II mammalian HDACs are differentially inhibited by structurally diverse compounds with known antitumor activities, thus presenting them as potential drug targets for human diseases resulting from aberrant acetylation.
Comment:Active center contains inhibitor and a catalytic Zn ion that coordinates side chain atoms of two aspartates and one histidine, and a water molecule.
Structure:2VQJ; human histone deacetylase 4 binds trifluoromethylketone inhbitor and a Zn ion; contacts at 4A.