Figure 6. The left-top panel.

The left-top panel – residues involved in the interface between Spike Receptor Binding Domain (RBD – colored in gray) and ACE2 receptor – colored in aquamarine.

The 3D insets - epitopes of antibodies binding to the RBD (RBD – gray, epitopes - orange spheres) and interface with human ACE2 receptor (blue).

The histograms – the prevalence of missense mutations in epitopes (red bars) and % of residue’s area in contact with ACE2 (blue bars).

Epitopes include residues whose solvent exposure decreases by at least 20% of their maximal solvent exposed area in the RBD-antibody complex as compared to RBD alone. Similarly, ACE2-contact area for any residue from RBD is the % of its solvent exposure lost when RBD is bound to ACE2. Antibody binding and ACE2 areas were derived from separate PDB entries (Ids of PDB entries used to define epitopes and RBD-ACE2 interface are shown above the 3D insets). For the purpose of comparison all epitopes are shown in the same structural context of the RBD-ACE2 complex (PDB id 6m0j) rather than in the context of the antibody RBD complexes. However, RBD may undergo some conformational changes in complexes with antibodies.