FIG. 6.

High GTP concentration requirement for de novo initiation on a mutant RNA template. The positive-strand RNA template containing the 3′-end sequence GGUUCU-3′ in the wild-type RNA was mutated to GGUUUU-3′ by PCR as described in Materials and Methods. RdRP assays were performed at 30°C by using fixed amounts of all components except GTP (A) or ATP (B). Products were analyzed by formaldehyde-agarose gel electrophoresis followed by autoradiography. The intensities of bands were quantified by using the imagej program as described in the Fig. 3 legend. ND, not done.