(C) 8-oxo-dG (orange) establishes a Watson-Crick base pair with dC (cyan) at the primer terminus. Tyr505, Arg517, and Glu529 (purple) interact with the minor groove of the base pair. The base pair geometry (C1′ distance and λ angles) is indicated at the bottom of the figure. A simulated annealing Fo-Fc omit density map for the pair is also shown (contoured at 3σ). 