Surface comparison of GBV-C and HCV RdRps. A, B, C correspond to different views of the GBV-C polymerase surfaces calculated using GRASP. The surface is colored according to the electrostatic potential. The red correspond to negative charges, the white is neutral, and the blue corresponds positive charges. D, E, F correspond to the surface of HCV polymerase in similar and respective orientations. The color ramp is the same as for the GBV-C polymerase surface.