Human protein kinase CK2 alpha in complex with 2-cyano-2-propenamide compound 3

Experimental Data Snapshot

  • Resolution: 1.70 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.161 
  • R-Value Observed: 0.163 

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A novel class of selective CK2 inhibitors targeting its open hinge conformation.

Dalle Vedove, A.Zonta, F.Zanforlin, E.Demitri, N.Ribaudo, G.Cazzanelli, G.Ongaro, A.Sarno, S.Zagotto, G.Battistutta, R.Ruzzene, M.Lolli, G.

(2020) Eur J Med Chem 195: 112267-112267

  • DOI: https://doi.org/10.1016/j.ejmech.2020.112267
  • Primary Citation of Related Structures:  
    6RB1, 6RCB, 6RCM, 6RFE, 6RFF

  • PubMed Abstract: 

    Protein kinase CK2 sustains cancer growth, especially in hematological malignancies. Its inhibitor SRPIN803, based on a 6-methylene-5-imino-1,3,4-thiadiazolopyrimidin-7-one scaffold, showed notable specificity. Our synthesis of the initially proposed SRPIN803 resulted in its constitutional isomer SRPIN803-revised, where the 2-cyano-2-propenamide group does not cyclise and fuse to the thiadiazole ring. Its crystallographic structure in complex with CK2α identifies the structural determinants of the reported specificity. SRPIN803-revised explores the CK2 open hinge conformation, extremely rare among kinases, also interacting with side chains from this region. Its optimization lead to the more potent compound 4, which inhibits endocellular CK2, significantly affects viability of tumour cells and shows remarkable selectivity on a panel of 320 kinases.

  • Organizational Affiliation

    Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Via Sommarive 9, 38123, Trento, 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
PHAROS:  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: 1.70 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.161 
  • R-Value Observed: 0.163 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 58.371α = 90
b = 46.38β = 111.93
c = 63.449γ = 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: 2020-04-08
    Type: Initial release
  • Version 1.1: 2020-04-22
    Changes: Database references
  • Version 1.2: 2024-01-24
    Changes: Data collection, Database references, Refinement description