Structural comparison of typical and atypical E2 pestivirus glycoproteins.

Pestiviruses, within the family Flaviviridae , are economically important viruses of livestock. In recent years, new pestiviruses have been reported in domestic animals and non-cloven-hoofed animals. Among them, atypical porcine pestivirus (APPV) and Norway rat pestivirus (NRPV) have relatively little sequence conservation in their surface glycoprotein E2. Despite E2 being the main target for neutralizing antibodies and necessary for cell attachment and viral fusion, the mechanism of viral entry remains elusive. To gain further insights into the pestivirus E2 mechanism of action and to assess its diversity within the genus, we report X-ray structures of the pestivirus E2 proteins from APPV and NRPV. Despite the highly divergent structures, both are able to dimerize through their C-terminal domain and contain a solvent-exposed β-hairpin reported to be involved in host receptor binding. Functional analysis of this β-hairpin in the context of BVDV revealed its ability to rescue viral infectivity. [Display omitted] • The X-ray crystal structures of APPV and NRPV E2 glycoproteins were determined • APPV and NRPV E2 form a dimer in solution Aitkenhead et al. report the X-ray crystal structures of pestivirus E2 surface glycoproteins from atypical porcine pestivirus and Norway rat pestivirus. These glycoproteins serve as primary targets for neutralizing antibodies and play crucial roles in cell attachment and viral fusion. [ABSTRACT FROM AUTHOR]