Fig. 2.

Buried SASA of monomers within spike trimer, compared between sub-groups. (a) Box and whisker plot for d-SASA distributions within each sub-group. (b) A scatter plot showing the ratio of non-polar to polar buried d-SASA for the S1 and S2 subunits, upon monomer burial in the trimer. Variation of this ratio is much greater for S1 than for S2 (seen with equal scaling of the axes), with higher values for the open form indicating that residual buried surface with RBD up is relatively non-polar.