8Q77

STRUCTURE OF PROTEIN KINASE CK2 CATALYTIC SUBUNIT (ISOFORM CK2ALPHA'; CSNK2A2 GENE PRODUCT) IN COMPLEX WITH THE BISUBSTRATE INHIBITOR ARC-780

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	6HMQ

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP		293	THE CK2ALPHA' SOLUTION AFTER PROTEIN PURIFICATION (5 MG/ML CK2ALPHA' IN 500 MM NACL, 25 MM TRIS/HCl, PH 8.5) WAS MIXED IN 1:10 VOLUME RATIO WITH 10 MM SOLUTION OF THE INHIBITOR MB002 IN DMSO. THIS SOLUTION WAS MIXED IN 2:1 RATIO WITH RESERVOIR SOLUTION [900 MM LICL, 28 % (W/V) PEG 6000, 250 MM TRIS/HCL, PH 8.5] IN SITTING DROP PLATES (VAPOUR DIFFUSION). THE CRYSTAL GROWTH WAS INDUCED BY MICROSEEDING. THE CRYSTALS WERE OPTIMIZED BY MACROSEEDING AND PURGED TWICE WITH RESERVOIR SOLUTION. THEN, ARC-780 WAS ADDED TO AN INITIAL CONCENTRATION OF 1 MM BY ADDING 1 MIKROLITER OF A 10 MM ARC-780 SOLUTION IN DMSO IN A 1:10 RATIO TO THE DROPLET. AFTER EXTENSIVE INTIAL SOAKING, THE SALT CONCENTRATION WAS SUCCESSIVELY LOWERED OVER A PERIOD OF 8 MONTHS WHILE IN PARALLEL THE CONCENTRATIONS OF DMSO AND PEG 6000 WERE INCREASED. THIS WAS DONE BY GRADUALLY REPLACING THE RESERVOIR AND THE DROPLET SOLUTION UNTIL ANY NACL WAS REMOVED, THE LICL CONCENTRATION WAS REDUCED TO 50 MM, THE PEG 6000 CONCENTRATION WAS INCREASED TO SATURATION AND A DMSO CONTENT OF 30% WAS REACHED. MEANWHILE, THE ARC-780 LIGAND WAS INCLUDED IN ANY DESALTING STEP REACHING SATURATION AFTER THE FINAL DILUTION STEP. ALL STEPS WERE PERFORMED AT A TEMPERATURE OF 293 K.

Crystal Properties
Matthews coefficient	Solvent content
2.66	53.84

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 46.603	α = 66.59
b = 47.919	β = 89.67
c = 51.031	γ = 88.16

Symmetry
Space Group	P 1

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	100	PIXEL	DECTRIS EIGER X 4M		2020-11-14	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	ESRF BEAMLINE MASSIF-3	0.9677	ESRF	MASSIF-3

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge I (Observed)	R Sym I (Observed)	Rrim I (All)	Rpim I (All)	CC (Half)	Net I Over Average Sigma (I)	Redundancy	Number Reflections (All)	Number Reflections (Observed)	Observed Criterion Sigma (F)	Observed Criterion Sigma (I)	B (Isotropic) From Wilson Plot
1	1.255	46.578	72.5	0.052	0.052	0.061	0.031	0.998	12.2	3.9		80300			10.32

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	R-Sym I (Observed)	Rrim I (All)	Rpim I (All)	CC (Half)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	1.255	1.364			0.559	0.559	0.648	0.326	0.806	1.6

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Resolution (High)	Resolution (Low)	Cut-off Sigma (F)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work	R-Free	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	FREE R-VALUE	1.255	41.25	2	80283	1214	72.45	0.1202	0.1197	0.157	16.47

Temperature Factor Modeling
Anisotropic B[1][1]	Anisotropic B[1][2]	Anisotropic B[1][3]	Anisotropic B[2][2]	Anisotropic B[2][3]	Anisotropic B[3][3]

RMS Deviations
Key	Refinement Restraint Deviation
f_dihedral_angle_d	18.2981
f_angle_d	1.7715
f_chiral_restr	0.1415
f_bond_d	0.023
f_plane_restr	0.0183

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	2768
Nucleic Acid Atoms
Solvent Atoms	311
Heterogen Atoms	153

Software

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

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729.