Fig. 1: Structural and sequence comparison of SARS-CoV-2 with seasonal human coronavirus spikes.

a Top panels: The structural distance between each overlayed amino acid in SARS-CoV-2 and its closest structural homologue in sHCoVs is mapped on a 3D model of SARS-CoV-2. The root mean square deviation (RMSD) in Ångstrom (Å), between the alpha-carbon of each amino acid (aa) of ancestral SARS-CoV-2 and seasonal human coronaviruses (sHCoVs) is color-coded from blue (overlapping; 0 Å) to red (≥3 Å). Residues that did not structurally align are depicted in grey. Bottom panels: Sequence conservation between aligned residues of SARS-CoV-2 and sHCoVs is highlighted in green. The S1 (left) and S2 domains (middle) are shown as color-coded ribbon models overlayed on a surface rendered model in grey. S-trimers (right) are shown in surface rendering to visualize exposed residues. b The minimum RMSD is plotted for the S1 and S2 domains and the monomer of the S-trimer that aligned best with SARS-CoV-2. c The frequency of identical aa out of total aa that structurally aligned best between the S1, S2, and monomer subunits of the S-trimers of SARS-CoV-2 and sHCoVs is shown.