Fig. 6.

A, B The sequence of SARS-CoV-2 RBD from residues 317 to 424 (A) and residues 425 to 532 (B), annotated with sequence of the RBM (underlined in B) and the 17 residues to which human ACE2 bind (blue shaded residues and asterisks). Additionally, mutations found in each of the major variants (yellow shaded residues; gray shaded for those mutations only found in some of the isolates of that variant), and epitopes for 40 antibodies known to target SARS-CoV-2 RBD (red letters/green shade) are provided. Purple shaded residues are those epitopes to which those particular antibodies bind to a second RBD at the distal end of the RBD (intraspike cross-linkers). The epitopes were retrieved from several references, including Barnes et al. [276], Yuan et al. [277], Niu et al. [435], Deshpande et al. [436], Dumet et al. [400], and Wang et al. [391]. Additional epitopes not adequately described in the literature were determined or corrected using the Protein Data Bank entries for the RBD-antibody co-crystal structures, with identification of the epitopes based on residues within 5 Å of the antibody CDR loops. The PDB ID entries used are provided in Table 5. Epitopes for IGM-6268 (COV2-14) and COV2-06 [244, 245] were determined based on mutational analysis, so are likely incomplete. At the right are notations for Classes into which Barnes et al. [276] placed these antibody epitopes (Classes 1-4), notations for how Yuan et al. [277] categorized the RBD-binding antibodies (RBS A-through-C and “S309-like” and “CR3022-like”), and the epitope groups into which we are currently placing these antibodies (RBD1-7, based on the epitope groupings described by Hastie et al. [290]. In this Figure, we are equating the epitope of sotrovimab with the antibody from which it was derived, S309. ACE2 angiotensin-converting enzyme-2, CDR complementarity determining region, PDB Protein Data Bank, RBD receptor binding domain, RBM receptor binding motif, RBS receptor binding site, SARS-CoV-2 severe acute respiratory syndrome coronavirus-2