Hepatitis C virus NS5B RNA polymerase (NS5B)

Hepatitis C virus NS5B RNA polymerase (NS5B) is a nonstructural protein that functions as an RNA-dependent RNA polymerase (RdRp). It is essential for the replication of the hepatitis C virus (HCV) genome and serves as a major target for antiviral drug development. NS5B catalyzes the polymerization of ribonucleoside triphosphates (rNTPs) during viral RNA replication, using the viral positive-sense RNA strand as a template. The enzyme can initiate RNA synthesis de novo. NS5B is approximately 66 kDa in size and its three-dimensional structure resembles a right hand with distinct 'fingers,' 'palm,' and 'thumb' domains. The active site responsible for catalysis resides within the palm domain. Targeting HCV’s unique RdRp allows selective inhibition without affecting host cellular processes.

Inhibition of RNA-dependent RNA polymerase activity, leading to chain termination or allosteric disruption of enzyme function.