Crystal structure of the KA1 domain from human Chk1

  • Classification: TRANSFERASE
  • Organism(s): Homo sapiens
  • Expression System: Escherichia coli
  • Mutation(s): No 

  • Deposited: 2017-07-18 Released: 2017-10-04 
  • Deposition Author(s): Emptage, R.P., Marmorstein, R.
  • Funding Organization(s): National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS), National Institutes of Health/National Cancer Institute (NIH/NCI)

Experimental Data Snapshot

  • Resolution: 2.50 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.217 

wwPDB Validation   3D Report Full Report

This is version 1.4 of the entry. See complete history


Intramolecular autoinhibition of checkpoint kinase 1 is mediated by conserved basic motifs of the C-terminal kinase-associated 1 domain.

Emptage, R.P.Schoenberger, M.J.Ferguson, K.M.Marmorstein, R.

(2017) J Biol Chem 292: 19024-19033

  • DOI: https://doi.org/10.1074/jbc.M117.811265
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Precise control of the cell cycle allows for timely repair of genetic material prior to replication. One factor intimately involved in this process is checkpoint kinase 1 (Chk1), a DNA damage repair inducing Ser/Thr protein kinase that contains an N-terminal kinase domain and a C-terminal regulatory region consisting of a ∼100-residue linker followed by a putative kinase-associated 1 (KA1) domain. We report the crystal structure of the human Chk1 KA1 domain, demonstrating striking structural homology with other sequentially diverse KA1 domains. Separately purified Chk1 kinase and KA1 domains are intimately associated in solution, which results in inhibition of Chk1 kinase activity. Using truncation mutants and site-directed mutagenesis, we define the inhibitory face of the KA1 domain as a series of basic residues residing on two conserved regions of the primary structure. These findings point to KA1-mediated intramolecular autoinhibition as a key regulatory mechanism of human Chk1, and provide new therapeutic possibilities with which to attack this validated oncology target with small molecules.

  • Organizational Affiliation

    From the Department of Biochemistry and Biophysics and the Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, emptage@upenn.edu.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
cDNA FLJ56409, highly similar to Serine/threonine-protein kinase Chk1 (EC
A, B
102Homo sapiensMutation(s): 0 
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
Experimental Data & Validation

Experimental Data

  • Resolution: 2.50 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.217 
  • Space Group: P 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 76.818α = 90
b = 76.818β = 90
c = 31.828γ = 120
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesF32-GM115098
National Institutes of Health/National Cancer Institute (NIH/NCI)United StatesP01-CA114046

Revision History  (Full details and data files)

  • Version 1.0: 2017-10-04
    Type: Initial release
  • Version 1.1: 2017-10-25
    Changes: Database references
  • Version 1.2: 2018-02-07
    Changes: Database references
  • Version 1.3: 2019-12-04
    Changes: Author supporting evidence
  • Version 1.4: 2023-10-04
    Changes: Data collection, Database references, Refinement description