TABLE 3.
Key residues on APN that determine the species specificity of group 1 coronavirus infection
| APN residue or region(s) (aa)a | Group 1 coronavirus(es) | Effect on coronavirus entry |
|---|---|---|
| 288-290 | HCoV-229E | Entry is blocked by the presence of an N-glycosylation sequon in mAPN and pAPN that is absent in fAPN and hAPN |
| T742 | TGEV, FCoV, CCoV | Entry via fAPN is blocked by substitution with V from mAPN or R from hAPN |
| R741 | TGEV | Entry via hAPN requires substitution with T from fAPN or pAPN |
| R1 (732-746) | TGEV | In an mAPN backbone, entry requires substitution of the R1 region from fAPN |
| R1 (732-746) and R2 (764-788) | FCoV, CCoV | In an mAPN backbone, entry requires the substitution of both the R1 and R2 regions from fAPN |
| N740 | CCoV | Entry requires the presence of this residue that is part of an N-glycosylation sequon and is conserved in most APN proteins |
a
All amino acid numbers correspond to fAPN, except for R741, the residue in hAPN homologous to T742 in fAPN.