Fig. 5: EEEV-373 binds a conformational epitope on the SINV/EEEV E2 protein.

A A close-up view of the E2 protein β-ribbon connector (cyan) and the E1 protein domain II (orange) interface, further highlighted by the dotted purple circle. The residues comprising the binding footprint of EEEV-373 are colored red. B A side view (rotated ~90°) of the E2/E1 interface is shown to highlight the significant interaction of the underlying E1 protein (orange) for the proper conformation and stabilization of the E2 protein β-ribbon connector (cyan). Residues involved in this interaction are indicated by the cyan or red spheres. The red spheres indicate the E2 residues that constitute the EEEV-373 epitope binding footprint. A detailed cartoon representation view (C) and a close-up, side view (rotated ~90°; D) of the interactions between the heavy chain complementarity-determining region loops (HCDR1, HCDR2, and HCDR3) of EEEV-373 (green) and the ‘arch 2’ cleft of the E2 protein β-ribbon connector (cyan). Specific view of the heavy chain CDR3 loop (HCDR3) of EEEV-373 (green) inserting within the ‘arch 2’ cleft of the E2 protein β-ribbon connector (cyan) as shown by the cartoon (E) or sphere (F) representations. The E2 protein β-ribbon connector residues that form the epitope binding footprint of EEEV-373 are indicated by the red spheres. Additional residues on the E2 protein within the immediate vicinity of the footprint are indicated by the cyan spheres. G The quality of the model fit to the map in the epitope-paratope region is coloured according to the Q-score. The corresponding color key is shown on the right.