9QAB | pdb_00009qab

Protein kinase CK2 catalytic subunit alpha' (CSNK2A2 gene product) in complex with F2X-Entry screen fragment E11 and CX-4945 (Silmitasertib)

• PDB DOI: https://doi.org/10.2210/pdb9QAB/pdb

• Classification: TRANSFERASE
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2025-02-28 Released: 2026-01-14 
• Deposition Author(s): Werner, C., Harasimowicz, H., Barthel, T., Weiss, M.S., Niefind, K.
• Funding Organization(s): German Research Foundation (DFG)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 0.95 Å
• R-Value Free: 
  0.141 (Depositor), 0.141 (DCC) 
• R-Value Work: 
  0.131 (Depositor), 0.131 (DCC) 
• R-Value Observed: 
  0.131 (Depositor) 

Starting Model: experimental

Literature

Crystallographic Fragment Screening with CK2 alpha', an Isoform of Human Protein Kinase CK2 Catalytic Subunit, and Its Use to Obtain a CK2 alpha'/Heparin Complex Structure

Werner, C., Barthel, T., Harasimowicz, H., Marminon, C., Weiss, M.S., Borgne, M.L., Niefind, K.

(2026) Kinases Phosphatases 4: 1

• DOI: https://doi.org/10.3390/kinasesphosphatases4010001

Biological Assembly 1  

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

Biological assembly 1 assigned by authors.

Macromolecule Content 

• Total Structure Weight: 44.22 kDa 
• Atom Count: 3,124 
• Modeled Residue Count: 327 
• Deposited Residue Count: 370 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Casein kinase II subunit alpha'	A	370	Homo sapiens	Mutation(s): 1  Gene Names: CSNK2A2, CK2A2 EC: 2.7.11.1
UniProt & NIH Common Fund Data Resources
Find proteins for P19784 (Homo sapiens) Explore P19784  Go to UniProtKB:  P19784
PHAROS:  P19784 GTEx:  ENSG00000070770

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
3NG	C [auth A]	5-[(3-chlorophenyl)amino]benzo[c][2,6]naphthyridine-8-carboxylic acid C19 H12 Cl N3 O2 MUOKSQABCJCOPU-UHFFFAOYSA-N
RA7 (Subject of Investigation/LOI)	B [auth A], D [auth A]	[2-(morpholin-4-yl)-1,3-thiazol-5-yl]methanol C8 H12 N2 O2 S VRNQHSDSVNEOKR-UHFFFAOYSA-N
CL	E [auth A]	CHLORIDE ION Cl VEXZGXHMUGYJMC-UHFFFAOYSA-M

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 0.95 Å
• R-Value Free:  0.141 (Depositor), 0.141 (DCC) 
• R-Value Work:  0.131 (Depositor), 0.131 (DCC) 
• R-Value Observed: 0.131 (Depositor) 

Space Group: P 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 46.437	α = 66.639
b = 47.76	β = 89.912
c = 50.492	γ = 88.612

Software Package:

Software Name	Purpose
PHENIX	refinement
PHASER	phasing
XDS	data reduction
Aimless	data scaling
autoPROC	data processing

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2026-01-14 
Deposition Author(s): Werner, C., Harasimowicz, H., Barthel, T., Weiss, M.S., Niefind, K.

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Funding Organization	Location	Grant Number
German Research Foundation (DFG)	Germany	NI 643/11-1

Revision History  

• Version 1.0: 2026-01-14
  Type: Initial release