Open Reading Frame 1 of the Norwalk-Like Virus Camberwell: Completion of Sequence and Expression in Mammalian Cells

The ORF1 sequence was determined for Camberwell virus, a genogroup 2 Norwalk-like virus, completing the full genome of 7,555 nucleotides. ORF1 cDNA was cloned into a simian virus 40-based expression vector, and the viral proteins synthesized following transfection into COS cells were analyzed. By using antisera directed against the helicase, protease, or polymerase regions, eight polypeptides ranging in size from 19 to 117 kDa were detected by radioimmunoprecipitation. The cleavage sites determining the amino and carboxy termini of the 3C-like protease were identified at E(1008)/A and E(1189)/G, respectively.