COMPLEX-FORMATION OF NS5B WITH NS3 AND NS4A PROTEINS OF HEPATITIS-C VIRUS

At present, the mechanism of replication of the HCV genome remains unc lear. Recently, NS5B and NS3 of HCV have been shown to exhibit RNA-dep endent RNA polymerase and helicase activities, respectively, both of w hich are indispensable for virus RNA replication. In this study, we ex amined the complex formation of NS5B with NS3 and NS4A, a cofactor for NS3. We show here that NS5B forms a complex with NS3 through an amino -terminal portion of NS3. The NS3-NS5B complex formation took place bo th in the presence and absence of NS4A. We also demonstrate that NS5B form a complex with NS4A in the absence of NS3. These results suggest that NS3, NS4A and NS5B interact with each other to form a complex tha t functions as part of the replication machinery of HCV. (C) 1998 Acad emic Press.