Veterinary and Biomedical Sciences, Department of


Date of this Version



Published in Virology 387:2 (May 10, 2009), pp. 331–340; doi 10.1016/j.virol.2009.02.019 Copyright © 2009 Elsevier Inc. Used by permission.


A selective trans-packaging system was developed to produce and isolate bovine viral diarrhea virus (BVDV) pseudo-particles with complementing reporter replicons and their packaging proteins expressed in trans with recombinant vaccinia virus. The encapsidation of replicon rNS3-5B was dependent not only on the in trans expression of structural proteins C, Erns, E1 and E2, but also the nonstructural proteins, p7 and contiguous precursor NS2-3-4A. Nonstructural p7, NS4B, NS5A or NS5B could be expressed in cis and in trans with precursor NS2-3-4A without significantly affecting virion assembly efficiency. NS2-3-4A was identified as an in trans functional precursor in virion assembly. BVDV genomes with mutant NS5B, which did not undergo active replication, were packaged 5-fold less efficiently than the intact genomes demonstrating the importance of replication in virion packaging. These results suggest that genome replication and assembly are closely associated, consistent with a model in which these two steps are coupled for maximum efficiency.