Human protein kinase CK2 alpha in complex with boldine

Experimental Data Snapshot

  • Resolution: 1.65 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.175 

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Inhibitory Properties of ATP-Competitive Coumestrol and Boldine Are Correlated to Different Modulations of CK2 Flexibility.

Battistutta, R.Lolli, G.

(2019) J Nat Prod 82: 1014-1018

  • DOI: https://doi.org/10.1021/acs.jnatprod.8b00889
  • Primary Citation of Related Structures:  
    6HNW, 6HNY

  • PubMed Abstract: 

    Casein kinase 2 (CK2) is an anti-apoptotic cancer-sustaining protein kinase. Its crystallographic structures with the natural compounds coumestrol, a phytoestrogen, and boldine, an alkaloid, are reported. Coumestrol shows different inhibitory activity against the isolated catalytic α-subunit and the α 2 β 2 holoenzyme and is able to discriminate between two conformations of the hinge/αD region, whose intrinsic flexibility is a relevant selectivity determinant among kinases. Boldine explores a small cavity at the bottom of the ATP-binding pocket through a local deviation from planarity, a unique case among CK2 inhibitors. The two compounds have different impacts on protein flexibility, which correlate with their different properties.

  • Organizational Affiliation

    Department of Cellular, Computational and Integrative Biology - CIBIO , University of Trento , Via Sommarive 9 , 38123 Povo (TN) , Italy.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Casein kinase II subunit alpha336Homo sapiensMutation(s): 0 
Gene Names: CSNK2A1CK2A1
UniProt & NIH Common Fund Data Resources
Find proteins for P68400 (Homo sapiens)
Explore P68400 
Go to UniProtKB:  P68400
GTEx:  ENSG00000101266 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP68400
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.65 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.175 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 58.513α = 90
b = 46.041β = 112.15
c = 63.184γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
Aimlessdata scaling
PDB_EXTRACTdata extraction

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-08-07
    Type: Initial release
  • Version 1.1: 2024-01-24
    Changes: Data collection, Database references, Refinement description