4A9R

CRYSTAL STRUCTURE OF HUMAN CHK2 IN COMPLEX WITH BENZIMIDAZOLE CARBOXAMIDE INHIBITOR


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.186 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

Benzimidazole Inhibitors of the Protein Kinase Chk2: Clarification of the Binding Mode by Flexible Side Chain Docking and Protein-Ligand Crystallography

Matijssen, C.Silva-Santisteban, M.C.Westwood, I.M.Siddique, S.Choi, V.Sheldrake, P.Van Montfort, R.L.M.Blagg, J.

(2012) Bioorg Med Chem 20: 6630

  • DOI: https://doi.org/10.1016/j.bmc.2012.09.024
  • Primary Citation of Related Structures:  
    4A9R, 4A9S, 4A9T, 4A9U

  • PubMed Abstract: 

    Two closely related binding modes have previously been proposed for the ATP-competitive benzimidazole class of checkpoint kinase 2 (CHK2) inhibitors; however, neither binding mode is entirely consistent with the reported SAR. Unconstrained rigid docking of benzimidazole ligands into representative CHK2 protein crystal structures reveals an alternative binding mode involving a water-mediated interaction with the hinge region; docking which incorporates protein side chain flexibility for selected residues in the ATP binding site resulted in a refinement of the water-mediated hinge binding mode that is consistent with observed SAR. The flexible docking results are in good agreement with the crystal structures of four exemplar benzimidazole ligands bound to CHK2 which unambiguously confirmed the binding mode of these inhibitors, including the water-mediated interaction with the hinge region, and which is significantly different from binding modes previously postulated in the literature.


  • Organizational Affiliation

    Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, Institute of Cancer Research, Haddow Laboratories, Sutton, Surrey, UK.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
SERINE/THREONINE-PROTEIN KINASE CHK2329Homo sapiensMutation(s): 0 
EC: 2.7.11.1
UniProt & NIH Common Fund Data Resources
Find proteins for O96017 (Homo sapiens)
Explore O96017 
Go to UniProtKB:  O96017
PHAROS:  O96017
GTEx:  ENSG00000183765 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO96017
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
RU5
Query on RU5

Download Ideal Coordinates CCD File 
C [auth A]2-[4-(4-CHLOROPHENOXY)PHENYL]-1H-BENZIMIDAZOLE-6-CARBOXAMIDE
C20 H14 Cl N3 O2
UXGJAOIJSROTTN-UHFFFAOYSA-N
EDO
Query on EDO

Download Ideal Coordinates CCD File 
D [auth A]1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
NO3
Query on NO3

Download Ideal Coordinates CCD File 
B [auth A]NITRATE ION
N O3
NHNBFGGVMKEFGY-UHFFFAOYSA-N
Binding Affinity Annotations 
IDSourceBinding Affinity
RU5 BindingDB:  4A9R IC50: min: 15, max: 100 (nM) from 3 assay(s)
PDBBind:  4A9R IC50: 16 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.186 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 90.84α = 90
b = 90.84β = 90
c = 93.35γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
MOSFLMdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-10-10
    Type: Initial release
  • Version 1.1: 2012-10-24
    Changes: Database references
  • Version 1.2: 2012-11-07
    Changes: Database references
  • Version 1.3: 2023-12-20
    Changes: Data collection, Database references, Derived calculations, Other, Refinement description