Histone deacetylase 1 (HDAC1) 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. HDAC1 is involved in regulation through association with DNA binding proteins to target specific chromatin regions. In particular, HDAC1 appears to play a major role in pre-implantation embryogenesis in establishing a repressive chromatin state. Its interaction with retinoblastoma tumor-suppressor protein is essential in the control of cell proliferation and differentiation. Together with metastasis-associated protein-2 (MTA2), it deacetylates p53, thereby modulating its effect on cell growth and apoptosis. It participates in DNA-damage response, along with HDAC2; together, they promote DNA non-homologous end-joining. HDAC1 is also involved in tumorogenesis; its overexpression modulates cancer progression. Specific inhibitors of HDAC1 are currently used in cancer therapy.
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.
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