PDS inhibits C-strand synthesis by inhibiting CST–PP binding to the template. (A) Representative gels showing C-strand synthesis in NaCl/KCl (left) or LiCl (right) with trace amount of radiolabeled template (T, 9xTEL) serving as recovery control. Twofold dilutions of PDS (highest concentration: 1600 nM) were incubated with the template before addition of CST–PP and NTPs. (B) Plot of relative synthesis intensities with T = 9xTEL at each concentration of PDS in NaCl/KCl or LiCl. Points represent mean values and error bars represent SD for n = 6 (Na+/K+) or n = 4 (Li+) independent experiments. (C,D) Same as A and B, respectively, but T = 9xnoGG. (E) Representative gels of CST–PP binding to the radiolabeled template in NaCl/KCl (left) or LiCl (right) following incubation of DNA with increasing concentrations of PDS (twofold dilutions from 1600 nM). (T) Template, (T–P) template–protein complex, (W) well. (F) Plot of fraction DNA bound at each concentration of PDS normalized to fraction bound with no inhibitor in NaCl/KCl or LiCl. Points represent mean values and error bars represent SD for n = 4 (Na+/K+) or n = 3 (Li+) replicates.
