Fig. 3.

The ACE2 receptor-interacting surface of high to moderate susceptibility groups. a Felis catus (high); b Equus caballus (high); c Panthera tigris altaica (high); d Oryctolagus cuniculus (moderate). The hydrogen-bonded and hydrophobic interactions formed between region 1 to region 3 with spike protein are shown. The natural substitution of residues is colored pink and yellow. In region 1 Q24L mutation in all four species disrupts the Q24-N487 hydrogen bond. In region 2, despite D30E mutation in all four bond formation is intact. Similarly in region3 and region 4 all the hydrogen bonding is conserved. Glycosylation sites (Site1-5, Asn 53, Asn 90, Asn 103, Asn 322, Asn546, respectively) are marked in red and substitution of glycosylating residue colored in green