Table 4.
Poxviruses entry proteins, cellular receptors and functions. 1, N-terminal, 2, C-terminal transmembrane domain
| Protein | Roles |
|---|---|
| Attachment | |
| A26 | Binds to laminin [185]; A25 and A26 may act as fusion suppressors [180, 186]. |
| A27 | Binds to heparan sulfate, but not chondroitin [187]; binds with A17 protein forming a complex that mediates pH-dependent cell-to-cell fusion and syncytium formation [188]. |
| D8 | Binds to chondroitin sulfate and mediates the adsorption of MV [189] |
| H3 | Binds to heparan sulfate [190] |
| Entry (entry-fusion complex, EFC) | |
| A16L | 2; interacts with G9 and with A56/K2 to prevent superinfection; A16-deficient virion fails to induce syncytia [191]. |
| A21L | 1; interacts with H2; [192] |
| A28L | 1; interacts with H2 and both are required for entry and cell-cell fusion [177, 179, 193–195]. |
| F9 | 2; important for entry; F9-deficient virus binds to the cell, but the core fails to penetrate into the inside [177, 196]. |
| G3L | 1 [197] |
| G9R | 2; binds to A16 and A26 suppressing fusion [198, 199]. |
| H2 | 1, binds to A28 and both are required for entry and cell-cell fusion [177, 179, 194, 195]. |
| J5 | 2 [200] |
| L1R | 2; binds with uninfected cell receptors; L1 mutant virus is lethal, as it is required in assembly and fusion [177, 196, 201] |
| L5R | 2 [202] |
| O3L | 1 [203] |