Structural Bases of Coronavirus Attachment to Host Aminopeptidase N and Its Inhibition by Neutralizing Antibodies
Figure 2
Crystal structure of the TGEV RBD in complex with the TGEV-neutralizing mAb 1AF10.
A. Ribbon diagram of the Fab fragment of the 1AF10 mAb bound to the TGEV RBD. Blue surface and ribbon representation is shown for the RBD domain, with β-strands and the terminal ends (n and c) where the remaining CoV S locates labeled. The antibody-binding regions at the tip are colored in red (β1–β2 region) and orange (β3–β4 and β5–β6). The 1AF10-Fab fragment is shown with heavy chain in grey and light chain in green. Variable (VH and VL) and constant (CH and CL) Ig domains of the Fab fragment are also indicated. B. Detailed view of the interaction, showing the RBD tip and the RBD-binding regions of the Fab variable domains. Buried regions are colored as in A for the RBD, and in dark green for the mAb. C. The RBD epitope for 1AF10. Surface and ribbon representation of the 1AF10 variable domains and stick drawing of buried residues at the interface, shown with carbons in orange or magenta for the RBD, and in green for the 1AF10 mAb. In this and following figures, nitrogens are in blue and oxygens in red, intermolecular hydrogen bonds are shown as dashed red lines, whereas intramolecular hydrogen bonds are black. D. Ligplot representation of 1AF10 mAb interaction with the RBD β1–β2 turn. RBD residues in the turn (magenta) and interacting mAb residues (green).