Histone deacetylase 2 (HDAC2) is a Zn-dependent class I enzyme that catalyzes hydrolysis of N(6)-acetyl-lysine residue of a histone to yield a deacetylated histone (EC 3.5.1.98). Histone acetylation/deacetylation process is important for mediation of transcriptional regulation of many genes. HDAC2 is involved in regulation through association with DNA binding proteins to target specific chromatin regions. It forms transcriptional repressor complexes by associating with several proteins, including the mammalian zinc-finger transcription factor YY1, thus playing an important role in transcriptional regulation, cell cycle progression and developmental events. Additionally, a few non-histone HDAC2 substrates have been found. HDAC2 plays a role in embryonic development and cytokine signaling important for immune response, and is over-expressed in several solid tumors including oral, prostate, ovarian, endometrial and gastric cancer. It participates in DNA-damage response, along with HDAC1; together, they can promote DNA non-homologous end-joining. HDAC2 is considered an important cancer prognostic marker. Inhibitors specifically targeting HDAC2 could be a therapeutic drug option.
Comment:Active site includes Zn binding site, lipophilic tube and foot pocket.
Comment:Active site consists of a long narrow tunnel (that apparently serves for substrate binding) and a cavity with Zn ion (that is important for catalysis). In this structure, the tunnel is filled by the aliphatic chain of the inhibitor.
Structure:3MAX: human histone deacetylase 2 binds amino benzamide (inhibitor) and Zn ion; contacts at 4A.