Ribavirin incorporation into s/s-AU and s/s-AC by FMDV WT and M296I 3Dpol. (A) RMP incorporation into s/s-AU by FMDV WT (•) and M296I (○) 3Dpol. Shown is a replot of the observed rate constants as a function of nucleotide concentration to yield a kpol of 0.03 s−1 and a Kd,app of 600 μM for WT FMDV 3Dpol and a kpol of 0.01 s−1 and a Kd,app of 1,000 μM for FMDV M296I 3Dpol. (B) RMP incorporation into s/s-AC by FMDV WT (•) and M296I (○) 3Dpol. Shown is a replot of the observed rate constants as a function of nucleotide concentration to yield a kpol of 0.02 s−1 and a Kd,app of 500 μM for WT FMDV 3Dpol and a kpol of 0.009 s−1 and a Kd,app of 800 μM for FMDV M296I 3Dpol.