Fig. 2: 6-thio-dGTP fails to inhibit replicative DNA polymerase δ holoenzyme.

a Schematic of the assay to monitor primer extension by Pol δ holoenzymes during a single binding encounter with a DNA substrate (BioCy5P/T, Supplementary Fig. 2a). PCNA (green) is assembled onto the substrate (250 nM), orientated toward the primer/template junction. Following the addition of physiological dNTP concentrations, DNA synthesis is initiated by adding 8.8 nM Pol δ. Created in BioRender. Sanford, S. (2025) https://BioRender.com/6ab6ej1. b Representative 16% denaturing gel of the primer extension products. The sizes of the primer (N) and the full-length product (N + 33) are indicated on the left, and the dNTP insertion step at each template C (c) is indicated on the right. c Quantification of DNA synthesis. The left panel shows the percent total primer extension plotted as a function of time. Data points after time = 0 s are fit to a linear regression. The right panel shows the percent of full-length products plotted as a function of reaction time. Data from reactions with natural dNTPs are shown in blue, and data from reactions in which 6-thio-dGTP replaced dGTP are shown in orange. Each data point represents the mean ± S.E.M. of three independent reactions. Source data are provided as a Source Data file.