8A55

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

Experimental procedure

Experimental method	MAD
Source type	SYNCHROTRON
Source details	ESRF BEAMLINE ID30B
Synchrotron site	ESRF
Beamline	ID30B
Temperature [K]	100
Detector technology	PIXEL
Collection date	2021-09-24
Detector	DECTRIS PILATUS 6M
Wavelength(s)	0.82656
Spacegroup name	P 43 21 2
Unit cell lengths	36.810, 36.810, 140.960
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	32.630 - 0.990
R-factor	0.1544
Rwork	0.153
R-free	0.17340
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	7k7p
Data reduction software	XDS
Data scaling software	XDS
Phasing software	PHENIX
Refinement software	PHENIX (1.19.1_4122)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	32.630	1.025
High resolution limit [Å]	0.990	0.990
Number of reflections	55025	5335
<I/σ(I)>	12.73	0.83
Completeness [%]	99.5	98.39
Redundancy	7.7	7.3
CC(1/2)	0.998	0.267

Crystallization Conditions

crystal 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.