5vi6
From Proteopedia
Crystal structure of histone deacetylase 8 in complex with trapoxin A
Structural highlights
Function[HDAC8_HUMAN] 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. May play a role in smooth muscle cell contractility.[1] [2] [3] [4] Publication Abstract from PubMedTrapoxin A is a microbial cyclic tetrapeptide that is an essentially irreversible inhibitor of class I histone deacetylases (HDACs). The inhibitory warhead is the alpha,beta-epoxyketone side-chain of (2S,9S)-2-amino-8-oxo-9,10-epoxydecanoic acid (l-Aoe), which mimics the side-chain of the HDAC substrate acetyl-l-lysine. We now report the crystal structure of the HDAC8-trapoxin A complex at 1.24 A resolution, revealing that the ketone moiety of l-Aoe undergoes nucleophilic attack to form a zinc-bound tetrahedral gem-diolate that mimics the tetrahedral intermediate and its flanking transition states in catalysis. Mass spectrometry, activity measurements, and isothermal titration calorimetry confirm that trapoxin A binds tightly (Kd = 3 +/- 1 nM) and does not covalently modify the enzyme, so the epoxide moiety of l-Aoe remains intact. Comparison of the HDAC8-trapoxin A complex with the HDAC6-HC toxin complex provides new insight regarding the inhibitory potency of l-Aoe-containing natural products against class I and class II HDACs. Binding of the Microbial Cyclic Tetrapeptide Trapoxin A to the Class I Histone Deacetylase HDAC8.,Porter NJ, Christianson DW ACS Chem Biol. 2017 Aug 30. doi: 10.1021/acschembio.7b00330. PMID:28846375[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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