Cloning，Sequence Analysis and Expression of Partial HCV Nonstructural Protein 2，3 Gene

Complementary DNA of partial HCV NS2 NS3 protein gene which encodes viral Zn 2+ dependent metalloprotease and serine protease was amplified by RT nested PCR from serum of a Chinese patient with chronic hepatitis C.The product was digested with Eco R Ⅰ/ Xba Ⅰ and cloned into pcDNA3.The nucleotide sequence was determined.Comparison of NS2 NS3 with the reported typical isolates HCV 1,HCV J,HC C2,HCV J6,HCV J8 showed as 73.72%,90.20%,91.02%,64.56%,63.37% identity in nucleotide sequence and 83.24%,92.09%,93.13%, 70.88% ,67.86% identity in amino acid sequence respectively, so the isolate could be classified as HCV genotype Ⅱ. This gene fragment was cloned into pBV220 to construct recombinant expression vector pBV220 NS2 3.It was expressed efficiently in E.coli . The cloning and expression of HCV NS2 NS3 may contribute to the investigation of the relation between structure and function of viral encoded protease.