crystal structure of Chek1 in complex with inhibitor 20

Experimental Data Snapshot

  • Resolution: 1.90 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.204 

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This is version 1.3 of the entry. See complete history


3-(Indol-2-yl)indazoles as Chek1 kinase inhibitors: Optimization of potency and selectivity via substitution at C6.

Fraley, M.E.Steen, J.T.Brnardic, E.J.Arrington, K.L.Spencer, K.L.Hanney, B.A.Kim, Y.Hartman, G.D.Stirdivant, S.M.Drakas, B.A.Rickert, K.Walsh, E.S.Hamilton, K.Buser, C.A.Hardwick, J.Tao, W.Beck, S.C.Mao, X.Lobell, R.B.Sepp-Lorenzino, L.Yan, Y.Ikuta, M.Munshi, S.K.Kuo, L.C.Kreatsoulas, C.

(2006) Bioorg Med Chem Lett 16: 6049-6053

  • DOI: https://doi.org/10.1016/j.bmcl.2006.08.118
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The development of 3-(indol-2-yl)indazoles as inhibitors of Chek1 kinase is described. Introduction of amides and heteroaryl groups at the C6 position of the indazole ring system provided sufficient Chek1 potency and selectivity over Cdk7 to permit escape from DNA damage-induced arrest in a cellular assay. Enzyme potency against Chek1 was optimized by the incorporation of a hydroxymethyl triazole moiety in compound 21 (Chek1 IC(50)=0.30nM) that was shown by X-ray crystallography to displace one of three highly conserved water molecules in the HI region of the ATP-binding cleft.

  • Organizational Affiliation

    Department of Medicinal Chemistry, Merck Research Laboratories, West Point, PA 19486, USA. alee7@prdus.jnj.com

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Serine/threonine-protein kinase Chk1322Homo sapiensMutation(s): 0 
Gene Names: CHEK1CHK1
UniProt & NIH Common Fund Data Resources
Find proteins for O14757 (Homo sapiens)
Explore O14757 
Go to UniProtKB:  O14757
PHAROS:  O14757
GTEx:  ENSG00000149554 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO14757
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on 710

Download Ideal Coordinates CCD File 
C24 H25 N7 O
Binding Affinity Annotations 
IDSourceBinding Affinity
710 Binding MOAD:  2HOG IC50: 0.3 (nM) from 1 assay(s)
PDBBind:  2HOG IC50: 0.3 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 1.90 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.204 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 44.97α = 90
b = 65.53β = 94.2
c = 58.4γ = 90
Software Package:
Software NamePurpose
d*TREKdata reduction
d*TREKdata scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-04-24
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-08-30
    Changes: Data collection, Database references, Derived calculations, Refinement description