The effect of free rNTPs on the processivity of WT and exo^- Pol γ.

<p>(<b>A</b>) Schematic diagram of the processivity assay carried out with WT and exo^- Pol γ on a primed, circular 3 kb template in the presence and absence of rNTPs. (<b>B</b>) Analysis of the processivity of WT and exo^- Pol γ as depicted in Fig 4A. Reactions were stopped after 10, 30, 60, and 90 min and the DNA products were analysed by agarose gel electrophoresis. All reactions were carried out in the presence of 750 nM mtSSB and 10 μM dNTPs. Where indicated, rNTPs were added. Fig 4B shows a representative figure of five (WT) and three (exo^-) independent experiments. See also <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007315#pgen.1007315.s004" target="_blank">S4 Fig</a>. (<b>C</b>) A plot of the signal intensity of the full-length product at each time point in Fig 4B. (<b>D</b>) Processivity was tested during an increasing amount of dNTPs (0, 2, 5, 10, 25 or 50 μM) with or without rNTPs at fixed concentration. Reactions were stopped after 60 min and analysed on TBE agarose gel. (<b>E</b>) To stimulate the conditions of imbalanced dNTP pools, each dNTP was limited to 1 μM (indicated dA, dG, dC or dT) and compared with “normal” dNTP conditions (indicated as N). Reactions run for 60 min, with or without rNTPs present and analysed on TBE agarose gel.