4x3o
Sirt2 in complex with a myristoyl peptide
Structural highlights
FunctionSIR2_HUMAN NAD-dependent protein deacetylase, which deacetylates internal lysines on histone and non-histone proteins. Deacetylates 'Lys-40' of alpha-tubulin. Involved in the control of mitotic exit in the cell cycle, probably via its role in the regulation of cytoskeleton. Deacetylates PCK1, opposing proteasomal degradation. Deacetylates 'Lys-310' of RELA.[1] [2] [3] [4] Publication Abstract from PubMedSirtuins are NAD-dependent deacylases. Previous studies have established two important enzymatic intermediates in sirtuin-catalyzed deacylation, an alkylamidate intermediate I, which is then converted to a bicyclic intermediate II. However, how intermediate II is converted to products is unknown. Based on potent SIRT2-specific inhibitors we developed, here we report crystal structures of SIRT2 in complexes with a thiomyristoyl lysine peptide-based inhibitor and carba-NAD or NAD. Interestingly, by soaking crystals with NAD, we capture a distinct covalent catalytic intermediate (III) that is different from the previously established intermediates I and II. In this intermediate, the covalent bond between the S and the myristoyl carbonyl carbon is broken, and we believe this intermediate III to be the decomposition product of II en route to form the end products. MALDI-TOF data further support the intermediate III formation. This is the first time such an intermediate has been captured by X-ray crystallography and provides more mechanistic insights into sirtuin-catalyzed reactions. Deacylation Mechanism by SIRT2 Revealed in the 1'-SH-2'-O-Myristoyl Intermediate Structure.,Wang Y, Fung YME, Zhang W, He B, Chung MWH, Jin J, Hu J, Lin H, Hao Q Cell Chem Biol. 2017 Mar 16;24(3):339-345. doi: 10.1016/j.chembiol.2017.02.007., Epub 2017 Mar 9. PMID:28286128[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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