2.1 Preparation of 3D structure of viral virulence factors as
receptors
The crystal structures of SARS-CoV-2 spike glycoprotein (S2; PDB code:
6VSB), viral nuclease (NSP15 endoribonuclease; PDB code: 6VWW) and
protease (Main Protease 3CLpro; PDB code: 1Q2W) were obtained from RCSB
Protein Data Bank (https://www.rcsb.org/). Hydrogen atoms were
introduced in all these 3D structures using Argus Lab (4.0.1), so as to
customize the viral receptors for rigid docking
(http://www.arguslab.com/arguslab.com/ArgusLab.html).