9S20 | pdb_00009s20

Crystal structure of human SIRT2 in complex with SirReal-triazole inhibitor SH10


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 
    0.182 (Depositor), 0.182 (DCC) 
  • R-Value Work: 
    0.160 (Depositor), 0.160 (DCC) 
  • R-Value Observed: 
    0.161 (Depositor) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

Validation slider image for 9S20

Ligand Structure Quality Assessment 


This is version 1.2 of the entry. See complete history

Literature

From Pharmacophore to Warhead: NAD + -Targeting Triazoles as Mechanism-Based Sirtuin Inhibitors.

Friedrich, F.Meleshin, M.Papenkordt, N.Gaitzsch, L.Prucker, I.Borso, M.Ruprecht, J.Vorreiter, C.Rast, S.Zhang, L.Schiedel, M.Sippl, W.Imhof, A.Jessen, H.J.Einsle, O.Schutkowski, M.Jung, M.

(2025) Angew Chem Int Ed Engl 64: e16782-e16782

  • DOI: https://doi.org/10.1002/anie.202516782
  • Primary Citation Related Structures: 
    9S1Z, 9S20, 9S21, 9S22, 9S23, 9S24, 9S25, 9S26, 9S27

  • PubMed Abstract: 

    Sirtuins (SIRTs) are nicotinamide adenine dinucleotide (NAD + )-dependent lysine deacylases linked to key physiological and disease processes. Here, we report a new class of mechanism-based 1,2,3-triazole inhibitors that hijack SIRT catalysis by forming stalled triazolium- or triazole-ADP-ribose (ADPR) adducts derived from the cofactor NAD + . These trapped adducts inhibit the enzyme without covalent protein modification, prompting us to term the compounds "Sirtuin Trapping Ligands" (SirTraps). X-ray crystallography and kinetics, together with mass spectrometry confirming adduct formation both in vitro and in cellulo, reveal that the triazole N3 of peptide- and small-molecule-based SirTraps triggers nucleophilic attack at C1' of the nicotinamide riboside moiety of NAD⁺, mimicking the first deacylation step. Adduct formation critically depends on precise triazole positioning within the acyl-lysine channel and can be tuned through scaffold design, enabling potent and isoform-selective inhibition. Unlike thiocarbonyl-based NAD⁺-targeting SIRT inhibitors, which may suffer from instability and off-target effects, SirTraps combine high stability, synthetic accessibility, and structural tunability, while demonstrating nanomolar cellular target engagement confirmed by NanoBRET assays. Beyond SIRTs, this inhibition strategy may extend to other NAD⁺-dependent enzymes, including ADP-ribosyltransferases, opening new avenues for mechanism-driven drug discovery.


  • Organizational Affiliation
    • Institute of Pharmaceutical Sciences, University of Freiburg, Albertstr. 25, 79104, Freiburg, Germany.

Macromolecule Content 

  • Total Structure Weight: 35.41 kDa 
  • Atom Count: 2,695 
  • Modeled Residue Count: 292 
  • Deposited Residue Count: 304 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
NAD-dependent protein deacetylase sirtuin-2304Homo sapiensMutation(s): 0 
Gene Names: SIRT2SIR2LSIR2L2
EC: 3.5.1 (PDB Primary Data), 2.3.1 (UniProt), 2.3.1.286 (UniProt)
UniProt & NIH Common Fund Data Resources
Find proteins for Q8IXJ6 (Homo sapiens)
Explore Q8IXJ6 
Go to UniProtKB:  Q8IXJ6
PHAROS:  Q8IXJ6
GTEx:  ENSG00000068903 
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8IXJ6
Sequence Annotations
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Reference Sequence

Small Molecules

Ligands 4 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
A1JK0
(Subject of Investigation/LOI)

Query on A1JK0



Download:Ideal Coordinates CCD File
F [auth A]2-(4,6-dimethylpyrimidin-2-yl)sulfanyl-~{N}-[5-[[3-[[1-[[4-(2-morpholin-4-ylethoxy)phenyl]methyl]-1,2,3-triazol-4-yl]methoxy]phenyl]methyl]-1,3-thiazol-2-yl]ethanamide
C34 H38 N8 O4 S2
CTNBHQJETORMIL-UHFFFAOYSA-N
BU3

Query on BU3



Download:Ideal Coordinates CCD File
C [auth A],
E [auth A]
(R,R)-2,3-BUTANEDIOL
C4 H10 O2
OWBTYPJTUOEWEK-QWWZWVQMSA-N
ZN

Query on ZN



Download:Ideal Coordinates CCD File
B [auth A]ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
EDO

Query on EDO



Download:Ideal Coordinates CCD File
D [auth A]1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free:  0.182 (Depositor), 0.182 (DCC) 
  • R-Value Work:  0.160 (Depositor), 0.160 (DCC) 
  • R-Value Observed: 0.161 (Depositor) 
Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 34.92α = 90
b = 77.165β = 93.78
c = 55.817γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
Aimlessdata scaling
autoPROCdata reduction
PHASERphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
German Research Foundation (DFG)GermanyJu295/18-1

Revision History  (Full details and data files)

  • Version 1.0: 2025-11-12
    Type: Initial release
  • Version 1.1: 2025-12-31
    Changes: Database references
  • Version 1.2: 2026-01-14
    Changes: Database references