Figure 2.

Congruence between binding score and structural homology analysis. Species classified by sequence identity to human ACE2 as very high (red) or high binding score (orange) have significantly fewer amino acid substitutions rated as potentially altering the binding interface between ACE2 and SARS-CoV-2 through protein structural analysis, as compared to low (green) or very low (blue) species. The more severe unfavorable variants are counted on y-axis and less severe weaken variants on the x-axis. Black numerical labels indicate species count.