REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
AlexaFluor680-conjugated AffiniPure Goat Anti Human IgG	JacksonImmuno	Cat# 109-625-098 Lot# 139337
Biological Samples
57BL/6J Mice	Jackson Laboratory	Cat# 000664
Chemicals, Peptides, and Recombinant Proteins
Thrombin	EMD Millipore	Ref# 605195 Lot# 2946006
One-GloEX	Promega	Cat# E8110
293-Free Transfection Reagent	Millipore Sigma	Cat# 72181
Lipofectamine-2000 Transfection Reagent	ThermoFisher	Cat# 11668500
Adjuvant	Sigma-Aldrich	Cat# S6322
Deposited Data
SARS-CoV-2 S CryoEM maps	This Paper	EMD: 21452, EMD: 21457
SARS-CoV-2 S atomic models	This Paper	PDB: 6VXX, PDB: 6VYB
Experimental Models: Cell Lines
Freestyle HEK293	ThermoFisher	Cat# R79007
HEK293T/17 adherent	Millet and Whittaker, 2016	ATCC CRL-11268
Vero(C1008)E6 adherent	ECACC General Collection	Cat# 85020206
Baby Hamster Kidney (BHK)	ATCC	Cat# CCL-10 Lot# 70009857
Recombinant DNA
pCMV-SARS-CoV-2 S 2P furin cleavage mutation	Genscript	N/A
pcD5 - ACE2	Raj et al., 2013	N/A
pcDNA3.1- SARS-CoV-2 SB	Genscript	N/A
pcDNA3.1- SARS-CoV SB	This paper	N/A
pcDNA3.1(-) –Full-length wild-type SARS-CoV-2 S	Genscript	N/A
pcDNA3.1(-) –Full-length wild-type SARS-CoV S	Millet and Whittaker, 2016	N/A
pCMV-murine leukemia virus gag-pol	Millet and Whittaker, 2016	N/A
pTG-Luciferase	Millet and Whittaker, 2016	N/A
Software and Algorithms
UCSF Chimera	Goddard et al., 2007	https://www.rbvi.ucsf.edu/chimera/
UCSF ChimeraX	Goddard et al., 2018	https://www.rbvi.ucsf.edu/chimerax/
Coot	Emsley et al., 2010	https://www2.mrc-lmb.cam.ac.uk/personal/pemsley/coot/
Relion	Scheres and Chen, 2012, Zivanov et al., 2019	https://www2.mrc-lmb.cam.ac.uk/relion/index.php?title=Main_Page
Rosetta	Frenz et al., 2019, Wang et al., 2016	https://www.rosettacommons.org/software
Leginon	Suloway et al., 2005	http://emg.nysbc.org/redmine/projects/leginon/wiki/Leginon_Homepage
WARP	Tegunov and Cramer, 2019	https://github.com/cramerlab/warp
CryoSPARC	Punjani et al., 2017	https://cryosparc.com
MolProbity	Chen et al., 2010	http://molprobity.biochem.duke.edu/
Other
Octet Red	ForteBio, Pall LLC	https://www.fortebio.com/products/label-free-bli-detection/8-channel-octet-systems
Anti-Penta-HIS (HIS1K)	ForteBio, Pall LLC	Part# 18-5120 Lot# 1910224A
HisTALON Superflow cartridge	Takara	Cat# 635683 Lot# 1509573A
HiTrap Protein A HP	GE Life Sciences	Cat# 29-0485-76
Superose 6 Increase 10/300	GE Life Sciences	Cat# 29-0915-96 Lot# 10226998
Lacey Formvar/Carbon 400 mesh, Cu Grids	Ted Pella	Prod# 01885-F Lot# 020218