Establishment of a cell-based assay system for hepatitis C virus serine protease and its primary applications

Figure 1 Schematic diagram of the pCI-neo-NS3/4A-SEAP and pCI-neo-RNS3/4A-SEAP expression vectors. The SEAP gene, which has N-terminal signal sequence, was fused in-frame to the HCV sequence encoding the full-length NS3 proteins followed by the NS4A cofactor. Amino acid sequences of (R)NS3/4A and SEAP in the fusion regions are shown by capitalized, bold characters. The cleavage site between NS4A and NS4B is indicated by arrow. HDS is the catalytic triad of NS3 protease.