Guanosine inhibits hepatitis C virus replication and increases indel frequencies, associated with altered intracellular nucleotide pools
Fig 8
Effect of nucleoside-triphosphate concentration on NS5BΔ21 RNA polymerase activity.
(A) Polyacrylamide gel showing the products for de novo (DN), primer extension (PE) and template switching (TS) obtained with HCV NS5BΔ21 at increasing concentrations (100, 500, 800, and 1000 μM) of UTP in the presence of radiolabeled α32P-CTP. ATP and GTP concentrations were maintained at 100 μM and 500 μM, respectively (left panel). Graphic representation of densitometric values obtained from the electropherogram shown in A (red diamonds, yellow triangles, and black squares correspond to de novo (DN), primer extension (PE), and template switching (TS) activities, respectively) (right panel). (B) Corresponds to experiments as in A but for increasing concentrations of ATP, with UTP and GTP maintained at 100 μM and 500 μM, respectively. (C) Corresponds to experiments as in A but for increasing concentrations of GTP, with ATP and UTP both maintained at 100 μM. Activities were normalized to their maximum values. Densitometric data represent the mean of at least three independent experiments. Error bars correspond to standard error of the mean. Horizontal lines indicate statistically significant differences (Student’s T-test) between the activity values that link, using the same color code as the activity type. Details of the activity measurements are given in Materials and Methods. Significance (Student’s T-test): *** p < 0.0005, ** p < 0.005, * p < 0.05.