- Enzymatic activities of the GB virus-B RNA-dependent RNA polymerase. Ranjith-Kumar, C.T., Santos, J.L., Gutshall, L.L., Johnston, V.K., Lin-Goerke, J., Kim, M.J., Porter, D.J., Maley, D., Greenwood, C., Earnshaw, D.L., Baker, A., Gu, B., Silverman, C., Sarisky, R.T., Kao, C. Virology (2003)