Biochemical characterization of the fidelity of poliovirus RNA-dependent RNA polymerase

Abstract
Putative high mutation rates of RNA viruses are believed to mediate undesirable phenomena, such as emergence of drug resistance. However, very little is known about biochemical fidelity rates for viral RNA-dependent RNA polymerases. Using a recently developed in vitro polymerase assay for poliovirus polymerase 3Dpol [Arnold and Cameron (2000) JBC 275:5329], we measured fidelity for each possible mismatch. Polymerase fidelity, in contrast to sequence error rate, is biochemically defined as kpol/Kd of {(correct plus incorrect) divided by incorrect} incorporations, such that a larger value connotes higher fidelity.