<p>VA14_26 and V1WT_41 bind epitopes that overlap with the RBD class 4 epitope.</p>

Contact residues for VA14_26 and V1WT_41 are indicated by red and pink dots and outline, respectively. Shared contact residues are shown with yellow dots and outline. <b>E)</b> Sequence alignment of a panel of SARS-CoV-2 variant RBDs. Contact residues for VA14_26 and V1WT_41 are indicated by red and pink dots and outline, respectively.

Shared contact residues are shown with yellow dots and outline. The colouring scheme describes the percent identity (PID) between the sequences as implemented in Jalview 2.11.4.0. <b>F)</b> A close-up view of YYDRSG motif in V1WT_41 HCDR3 (green) in contact with WIV-1 RBD (grey), shown in stick representation, renumbered based on alignment to SARS-CoV-2 [<a href="plosbiology.org/article/info:doi/10.1371/journal.pbio.3003882#pbio.3003882.ref038" target="_blank">38</a>,<a href="plosbiology.org/article/info:doi/10.1371/journal.pbio.3003882#pbio.3003882.ref039" target="_blank">39</a>].

Presence of G109 breaks the H-bonding pattern in the beta hairpin to create a G1 β-bulge. This further enables D106 side chain to make hydrogen bond with the amides in the protein backbone, thereby stabilising the local structure. Combined this accentuates a right-handed twist found in G1 β-bulge [<a href="plosbiology.org/article/info:doi/10.1371/journal.pbio.3003882#pbio.3003882.ref083" target="_blank">83</a>].

Twisting of the β-hairpin is thought to contribute towards stabilisation of RBD-Fab interaction in several other public mAbs with YYDRxG motif [<a href="plosbiology.org/article/info:doi/10.1371/journal.pbio.3003882#pbio.3003882.ref038" target="_blank">38</a>,<a href="plosbiology.org/article/info:doi/10.1371/journal.pbio.3003882#pbio.3003882.ref039" target="_blank">39</a>].</p>