8xe7
Crystal structure of human Sirt2 without Sirt2-specific insertion
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 PubMedSirtuin 2 (SIRT2) is a class III histone deacetylase that is highly conserved from bacteria to mammals. We prepared and characterized the wild-type (WT) and mutant forms of the histone deacetylase (HDAC) domain of human SIRT2 (hSIRT2) using various biophysical methods and evaluated their deacetylation activity. We found that WT hSIRT2 HDAC (residues 52-357) forms a homodimer in a concentration-dependent manner with a dimer-monomer dissociation constant of 8.3 +/- 0.5 muM, which was determined by mass spectrometry. The dimer was disrupted into two monomers by binding to the HDAC inhibitors SirReal1 and SirReal2. We also confirmed dimer formation of hSIRT2 HDAC in living cells using a NanoLuc complementation reporter system. Examination of the relationship between dimer formation and deacetylation activity using several mutants of hSIRT2 HDAC revealed that some non-dimerizing mutants exhibited deacetylation activity for the N-terminal peptide of histone H3, similar to the wild type. The hSIRT2 HDAC mutant Delta292-306, which lacks a SIRT2-specific disordered loop region, was identified to exist as a monomer with slightly reduced deacetylation activity; the X-ray structure of the mutant Delta292-306 was almost identical to that of the WT hSIRT2 HDAC bound to an inhibitor. These results indicate that hSIRT2 HDAC forms a dimer, but this is independent of deacetylation activity. Herein, we discuss insights into the dimer formation of hSIRT2 based on our biophysical experimental results. Biophysical insights into the dimer formation of human Sirtuin 2.,Suzuki N, Konuma T, Ikegami T, Akashi S Protein Sci. 2024 May;33(5):e4994. doi: 10.1002/pro.4994. PMID:38647411[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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