Inhibition of Replicative and Translesion Polymerases by Intramolecular G-quadruplexes.

<p>In primer extension assays containing 75(3×GGG/*P31) and G-quadruplex-forming (4×GGG/*P31 or ext-4×GGG/*P31) substrates (0.2–0.3 nM) were incubated with increasing concentrations of the following polymerases: Kexo⁻ (10 and 20 U/L), T4 DNA polymerase (50 and 100 U/L), pol δ (3.4, 8.6, and 17.1 nM), human pol η (0.10 and 0.26 nM), pol κ (1.3 and 2.5 nM), pol μ (5.5, 10.9, and 27.3 nM), or pol β (11.6, 23.2, and 46.3 nM). Incubation temperatures and times for individual polymerases are specified above the gel. Markers (M) generated by 3×GGG/*P31 extension using dATP and dTTP only and Kexo⁻ (lanes 4, 15, 39, and 49) or T4 DNA polymerase (lanes 5, 16, 40, and 50) are denoted. Positions of partial extension products indicating polymerase stalling are denoted with brackets. White dashed lines indicate where separated groups of lanes from a single gel have been spliced together.