trans Activity of the Norovirus Camberwell Proteinase and Cleavage of the N-Terminal Protein Encoded by ORF1

Abstract

The virus-encoded proteinase of Camberwell virus, a genogroup 2 norovirus, was synthesized in Escherichia coli . The purified proteinase had correct N and C termini and showed trans activity in cell-free assays. trans activity was also demonstrated in COS cells transfected with constructs encoding either the proteinase or a proteinase-polymerase fusion. The N-terminal protein of ORF1 was cleaved in COS cells, possibly at the site E 194 /S.