Characterization, cloning and expression of NS3 protein gene of hepatitis C genotype 4a.

Clone and express NS3 gene of the Egyptian strain ED43 of HCV genotype 4a in E. coli was studied. Gene and protein sequences of NS3 gene of the ED43 strain were first analyzed using PC/GENE program. DNA homology was 89% the homologies and that of the protein was 78.8% indicating that NS3 gene of the genotype 4a is different from those isolated from other strains. DNA of NS3 region of genotype 4a was amplified from HCV_ED43/PUC19 plasmid. The PCR product was cloned and expressed in E. coli M15 using pQE-30 vector. Fusion protein containing the peptides coded by HCV NS3 (NS3_4a) was expressed by Escherichia coli. The specific HCV antigenicity of the NS3_4a fusion protein was identified by western blotting.