8A55

Structure of N-terminal SARS-CoV-2 nonstructural protein 1 (nsp1) at atomic resolution

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP		291.15	Commercial screen Index 44 (0.1 M HEPES pH 7.5, 25% w/v PEG3350) was chosen for SARS-CoV-2 nsp1 (residues 10 to 126) crystallisation in large quantities using hanging drop method. Frozen stocks of SARS-CoV-2 nsp1 (residues 10 to 126) were thawed on ice and centrifuged in a Thermo Scientific Pico 17 Microcentrifuge, 24-Pl Rotor at 4 degrees, 20000 rpm for 10 min to remove aggregates before the determination of the protein concentration. Subsequently, the protein stock was diluted to 20 mg/mL with precrystallisation buffer (10 mM HEPES and 300 mM NaCl). 400 uL of Index condition 44 was added into each reservoir well. Five protein drops were set on each cover slip by mixing 1 uL of protein solution with 1 uL of the reservoir. The 24-well Linbro plates were incubated at 18 degrees.

Crystal Properties
Matthews coefficient	Solvent content
1.82	32.46

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 36.81	α = 90
b = 36.81	β = 90
c = 140.96	γ = 90

Symmetry
Space Group	P 43 21 2

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 PILATUS 6M		2021-09-24	M	MAD

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	ESRF BEAMLINE ID30B	0.82656	ESRF	ID30B

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	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	0.99	32.63	99.49	0.998	12.73	7.7		55025

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	CC (Half)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	0.99	1.025	98.39		0.267	0.83	7.3

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	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	THROUGHOUT	7K7P	0.99	32.63	1.34	55001	2752	99.5	0.1544	0.1534	0.1734	24.5782

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]

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	909
Nucleic Acid Atoms
Solvent Atoms	132
Heterogen Atoms

Software

Software
Software Name	Purpose
PHENIX	refinement
XDS	data scaling
PHENIX	phasing
PDB_EXTRACT	data extraction
XDS	data reduction

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 R01GM133198.