Crystal Structure of CHK1 with a Urea Inhibitor

Experimental Data Snapshot

  • Resolution: 2.90 Å
  • R-Value Free: 0.297 
  • R-Value Work: 0.218 
  • R-Value Observed: 0.241 

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This is version 1.3 of the entry. See complete history


Synthesis and biological evaluation of 1-(2,4,5-trisubstituted phenyl)-3-(5-cyanopyrazin-2-yl)ureas as potent Chk1 kinase inhibitors

Li, G.Hasvold, L.A.Tao, Z.-F.Wang, G.T.Gwaltney II, S.L.Patel, J.Kovar, P.Credo, R.B.Chen, Z.Zhang, H.Park, C.Sham, H.L.Sowin, T.Rosenberg, S.H.Lin, N.-H.

(2006) Bioorg Med Chem Lett 16: 2293-2298

  • DOI: https://doi.org/10.1016/j.bmcl.2006.01.028
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Based on the X-ray crystallography of our lead compound 1-(5-chloro-2,4-dimethoxyphenyl)-3-(5-cyanopyrazin-2-yl)urea in the checkpoint kinase 1 (Chk1) enzyme, we modified R4, and to a lesser extent, R2, and R5 of the phenyl ring, and made a variety of N-aryl-N'-pyrazinylurea Chk1 inhibitors. Enzymatic activity less than 20 nM was observed in 15 of 41 compounds. Compound 8i provided the best overall results in the cellular assays as it abrogated doxorubicin-induced cell cycle arrest (IC50=1.7 microM) and enhanced doxorubicin cytotoxicity (IC50=0.44 microM) while displaying no single agent activity.

  • Organizational Affiliation

    Cancer Research, Global Pharmaceutical Research & Development, Abbott Laboratories, Abbott Park, IL 60064, USA. Gaoquan.Li@abbott.com

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Serine/threonine-protein kinase Chk1269Homo 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 A42

Download Ideal Coordinates CCD File 
C14 H12 Cl N5 O3
Binding Affinity Annotations 
IDSourceBinding Affinity
A42 BindingDB:  2YWP Ki: 10 (nM) from 1 assay(s)
IC50: 7 (nM) from 1 assay(s)
PDBBind:  2YWP IC50: 7 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 2.90 Å
  • R-Value Free: 0.297 
  • R-Value Work: 0.218 
  • R-Value Observed: 0.241 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 44.863α = 90
b = 65.513β = 94.07
c = 57.84γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

  • Released Date: 2007-05-08 
  • Deposition Author(s): Park, C.
  • This entry supersedes: 2FGA

Revision History  (Full details and data files)

  • Version 1.0: 2007-05-08
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2024-03-13
    Changes: Data collection, Database references, Derived calculations