A Cryptic Site of Vulnerability on the Receptor Binding Domain of the SARS-CoV-2 Spike Glycoprotein

M. Gordon Joyce; Rajeshwer S. Sankhala; Wei-Hung Chen; Misook Choe; Hongjun Bai; Agnes Hajduczki; Lianying Yan; Spencer L. Sterling; Caroline E. Peterson; Ethan C. Green; Clayton Smith; Natalia de Val; Mihret Amare; Paul Scott; Eric D. Laing; Christopher C. Broder; Morgane Rolland; Nelson L. Michael; Kayvon Modjarrad

Phenix xtriage was used to analyze the scaled diffraction data produced from HKL2000 and XDS. Data was analyzed for completeness, Matthew's coefficient, twinning or pseudo-translational pathology. The structure of the SARS-CoV-2 RBD was determined by molecular replacement using Phaser and a search model of the SARS RBD (PDB ID: 2AJF, molecule C). CR3022 Fab crystal structure was determined by molecular replacement using Coxsackievirus A6 neutralizing antibody 1D5 (PDB ID: 5XS7) as a search model. The CR3022-RBD complex structure was determined by molecular replacement using the refined CR3022 and SARS-CoV-2 RBD structures as search models. Refinement was carried out using Phenix refine with positional, global isotropic B factor refinement, and defined TLS groups, with iterative cycles of manual model building using COOT. Structure quality was assessed with MolProbity. The final refinement statistics for all the structures are reported in Table 1 . All structure figures were generated using PyMOL (The PyMOL Molecular Graphics System [DeLano Scientific]).