4BV2 image
Deposition Date 2013-06-24
Release Date 2013-07-17
Last Version Date 2024-11-13
Entry Detail
PDB ID:
4BV2
Keywords:
Title:
CRYSTAL STRUCTURE OF SIR2 IN COMPLEX WITH THE INHIBITOR EX-527, 2'-O-ACETYL-ADP-RIBOSE AND DEACETYLATED P53-PEPTIDE
Biological Source:
Source Organism:
THERMOTOGA MARITIMA (Taxon ID: 2336)
HOMO SAPIENS (Taxon ID: 9606)
Host Organism:
Method Details:
Experimental Method:
Resolution:
3.30 Å
R-Value Free:
0.31
R-Value Work:
0.24
R-Value Observed:
0.24
Space Group:
P 43
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:NAD-DEPENDENT PROTEIN DEACETYLASE
Gene (Uniprot):cobB
Chain IDs:A, B
Chain Length:246
Number of Molecules:2
Biological Source:THERMOTOGA MARITIMA
Polymer Type:polypeptide(L)
Molecule:CELLULAR TUMOR ANTIGEN P53
Gene (Uniprot):TP53
Chain IDs:C (auth: E), D (auth: H)
Chain Length:13
Number of Molecules:2
Biological Source:HOMO SAPIENS
Primary Citation
Ex-527 Inhibits Sirtuins by Exploiting Their Unique Nad+-Dependent Deacetylation Mechanism
Proc.Natl.Acad.Sci.USA 110 E2772 ? (2013)
PMID: 23840057 DOI: 10.1073/PNAS.1303628110

Abstact

Sirtuins are protein deacetylases regulating metabolism and stress responses. The seven human Sirtuins (Sirt1-7) are attractive drug targets, but Sirtuin inhibition mechanisms are mostly unidentified. We report the molecular mechanism of Sirtuin inhibition by 6-chloro-2,3,4,9-tetrahydro-1H-carbazole-1-carboxamide (Ex-527). Inhibitor binding to potently inhibited Sirt1 and Thermotoga maritima Sir2 and to moderately inhibited Sirt3 requires NAD(+), alone or together with acetylpeptide. Crystal structures of several Sirtuin inhibitor complexes show that Ex-527 occupies the nicotinamide site and a neighboring pocket and contacts the ribose of NAD(+) or of the coproduct 2'-O-acetyl-ADP ribose. Complex structures with native alkylimidate and thio-analog support its catalytic relevance and show, together with biochemical assays, that only the coproduct complex is relevant for inhibition by Ex-527, which stabilizes the closed enzyme conformation preventing product release. Ex-527 inhibition thus exploits Sirtuin catalysis, and kinetic isoform differences explain its selectivity. Our results provide insights in Sirtuin catalysis and inhibition with important implications for drug development.

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