Figure 6: Comparison of all known HAstV-neutralizing antibody epitopes, showing that most target the upper variable region of HAstV spike.

(A) Alignment of all existing HAstV neutralizing antibody structures 4B6, 3B4, 3H4, 3E8, 2D9, and PL-2, mapped onto HAstV1 spike. (B) Spike protein sequences of the eight classical HAstV serotypes aligned using EMBL-MUSCLE, with residues colored according to conservation. The following sequences were used for the alignment: HAstV1, GenBank #AAC34717.1; HAstV2, GenBank # KY964327.1; HAstV3, UniProt #Q9WFZ0.1; HAstV4, UniProt #Q3ZN05.1; HAstV5, UniProt #Q4TWH7.1; HAstV6, UniProt #Q67815.1; HAstV7, UniProt #Q96818.2; HAstV8, UniProt #Q9IFX1.2. Residue numbering shown above corresponds with HAstV2. Residues highlighted in red are strictly conserved, residues with red text are semi-conserved, and residues in black text have little to no conservation. Spike residues interacting with the antibodies characterized in this paper, 3H4, 3B4, and 4B6, are indicted with colored squares, and epitope residues for antibodies that were previously characterized, 2D9, 3E8, and PL-2, are indicated as colored circles.