1IA8 | pdb_00001ia8

THE 1.7 A CRYSTAL STRUCTURE OF HUMAN CELL CYCLE CHECKPOINT KINASE CHK1

• PDB DOI: https://doi.org/10.2210/pdb1IA8/pdb

• Classification: TRANSFERASE
• Organism(s): Homo sapiens
• Expression System: Spodoptera frugiperda
• Mutation(s): No 


• Deposited: 2001-03-22 Released: 2001-04-18 
• Deposition Author(s): Chen, P., Luo, C., Deng, Y., Ryan, K., Register, J., Margosiak, S., Tempczyk-Russell, A., Nguyen, B., Myers, P., Lundgren, K., Chen Kan, C.-C., O'Connor, P.M.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.70 Å
• R-Value Free: 
  0.235 (Depositor) 
• R-Value Work: 
  0.216 (Depositor) 

Starting Model: experimental

Literature

The 1.7 A crystal structure of human cell cycle checkpoint kinase Chk1: implications for Chk1 regulation.

Chen, P., Luo, C., Deng, Y., Ryan, K., Register, J., Margosiak, S., Tempczyk-Russell, A., Nguyen, B., Myers, P., Lundgren, K., Kan, C.C., O'Connor, P.M.

(2000) Cell 100: 681-692

• PubMed: 10761933 
• DOI: https://doi.org/10.1016/s0092-8674(00)80704-7
• Primary Citation Related Structures: 
  1IA8


• PubMed Abstract: 
  

  The checkpoint kinase Chk1 is an important mediator of cell cycle arrest following DNA damage. The 1.7 A resolution crystal structures of the human Chk1 kinase domain and its binary complex with an ATP analog has revealed an identical open kinase conformation. The secondary structure and side chain interactions stabilize the activation loop of Chk1 and enable kinase activity without phosphorylation of the catalytic domain. Molecular modeling of the interaction of a Cdc25C peptide with Chk1 has uncovered several conserved residues that are important for substrate selectivity. In addition, we found that the less conserved C-terminal region negatively impacts Chk1 kinase activity.

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Organizational Affiliation: 
• Agouron Pharmaceuticals, Inc. San Diego, California 92121, USA. [e-mail]

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content 

• Total Structure Weight: 33.14 kDa 
• Atom Count: 2,370 
• Modeled Residue Count: 272 
• Deposited Residue Count: 289 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
CHK1 CHECKPOINT KINASE	A	289	Homo sapiens	Mutation(s): 0  EC: 2.7.1 (PDB Primary Data), 2.7.11.1 (UniProt)
UniProt & NIH Common Fund Data Resources
Find proteins for O14757 (Homo sapiens) Explore O14757  Go to UniProtKB:  O14757
PHAROS:  O14757 GTEx:  ENSG00000149554

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
SO4	B [auth A]	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.70 Å
• R-Value Free:  0.235 (Depositor) 
• R-Value Work:  0.216 (Depositor) 

Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 45.2	α = 90
b = 65.7	β = 93.9
c = 58.1	γ = 90

Software Package:

Software Name	Purpose
AMoRE	phasing
PHASES	phasing
X-PLOR	refinement
DENZO	data reduction
SCALEPACK	data scaling

Structure Validation

Entry History 

Deposition Data

• Released Date: 2001-04-18 
Deposition Author(s): Chen, P., Luo, C., Deng, Y., Ryan, K., Register, J., Margosiak, S., Tempczyk-Russell, A., Nguyen, B., Myers, P., Lundgren, K., Chen Kan, C.-C., O'Connor, P.M.

Revision History  

• Version 1.0: 2001-04-18
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2018-01-31
  Changes: Experimental preparation
• Version 1.4: 2024-02-07
  Changes: Data collection, Database references, Derived calculations
• Version 1.5: 2024-04-03
  Changes: Refinement description