HCV is a positive, single-stranded RNA virus in the Flaviviridae family. The genome is approximately 10,000 nucleotides and encodes a single polyprotein of about 3,000 amino acids. The polyprotein is processed by host cell and viral proteases into three major structural proteins, and several non-structural proteins necessary for viral replication, of which NS5B is one. NS5B RNA-dependant RNA polymerase is responsible for replication of the hepatitis C viral genome, and is currently a principal target for chemotherapeutic inhibition of HCV replication. Hepatitis C virus (HCV) can cause chronic hepatitis, cirrhosis and hepatocellular carcinoma. At present there is no vaccine effective against HCV. Host membrane insertion occurs after processing by the NS3 protease.