2X8I

Discovery of a Novel Class of triazolones as Checkpoint Kinase Inhibitors - Hit to Lead Exploration

• PDB DOI: https://doi.org/10.2210/pdb2X8I/pdb

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


• Deposited: 2010-03-09 Released: 2010-08-11 
• Deposition Author(s): Read, J.A., Breed, J., Haye, H., McCall, E., Otterbein, L., Vallentine, A., White, A.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.92 Å
• R-Value Free: 0.224 
• R-Value Work: 0.188 
• R-Value Observed: 0.189 

Starting Model: experimental

Literature

Discovery of a Novel Class of Triazolones as Checkpoint Kinase Inhibitors-Hit to Lead Exploration.

Oza, V., Ashwell, S., Brassil, P., Breed, J., Deng, C., Ezhuthachan, J., Haye, H., Horn, C., Janetka, J., Lyne, P., Newcombe, N., Otterbien, L., Pass, M., Read, J.A., Roswell, S., Su, M., Toader, D., Yu, D., Yu, Y., Valentine, A., Webborn, P., White, A., Zabludoff, S., Zheng, X.

(2010) Bioorg Med Chem 20: 5133

• PubMed: 20673630 
• DOI: https://doi.org/10.1016/j.bmcl.2010.07.015
• Primary Citation of Related Structures:  
  2X8D, 2X8E, 2X8I


• PubMed Abstract: 
  

  Checkpoint Kinase-1 (Chk1, CHK1, CHEK1) is a Ser/Thr protein kinase that mediates cellular responses to DNA-damage. A novel class of Chk1 inhibitors, triazoloquinolones/triazolones (TZ's) was identified by high throughput screening. The optimization of these hits to provide a lead series is described.

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Organizational Affiliation: 

AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, MA 02451, USA. [e-mail]

Biological Assembly 1  

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

Biological assembly 1 generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 33.62 kDa 
• Atom Count: 2,387 
• Modelled Residue Count: 261 
• Deposited Residue Count: 289 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
SERINE/THREONINE-PROTEIN KINASE CHK1	A	289	Homo sapiens	Mutation(s): 0  EC: 2.7.11.1
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 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
X8I	B [auth A]	7-(3-hydroxyphenyl)-5-methyl[1,2,4]triazolo[4,3-a]quinolin-1(2H)-one C17 H13 N3 O2 UWWPFTOELGGCIL-UHFFFAOYSA-N
SO4	C [auth A], D [auth A]	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L
GOL	E [auth A]	GLYCEROL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N

Binding Affinity Annotations
ID	Source	Binding Affinity
X8I	PDBBind:  2X8I	IC50: 190 (nM) from 1 assay(s)

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.92 Å
• R-Value Free: 0.224 
• R-Value Work: 0.188 
• R-Value Observed: 0.189 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 41.255	α = 90
b = 70.9	β = 90
c = 104.241	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
MOSFLM	data reduction
SCALA	data scaling
AMoRE	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2010-08-11 
Deposition Author(s): Read, J.A., Breed, J., Haye, H., McCall, E., Otterbein, L., Vallentine, A., White, A.

Revision History  

• Version 1.0: 2010-08-11
  Type: Initial release
  
• Version 1.1: 2011-05-08
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2019-05-08
  Changes: Data collection, Experimental preparation, Other
• Version 1.4: 2019-07-24
  Changes: Data collection
• Version 1.5: 2023-12-20
  Changes: Data collection, Database references, Derived calculations, Other, Refinement description