Fig. 1: Salient features of the structure.
From: Structure of a DNA polymerase abortive complex with the 8OG:dA base pair at the primer terminus
a Structure of the active site of DNA polymerase β showing the abortive ternary complex formed through dynamics in the DNA polymerase β active site, as a function of the 8OG:dA base pair in the template (8OG):primer (dA) position of a single-nucleotide gap substrate DNA. A simulated-annealing omit map contoured at 3σ is shown in green for the extra-helical base, incoming dCMPP(CH2)P and the newly inserted dCMP as the primer terminus. b Overlay of the 8OG:dA base pair from the current structure (gold) on a reference ternary complex structure (PDB ID 3RJH) shown as a wire representation (cyan). Surprisingly, the current structure shows 8OG in the anti-conformation forming a wobble base pair with newly inserted dCMP. The 8OG:dA base pair in the primer position of the starting binary complex had been disrupted. The reference ternary complex structure shows the syn conformation of 8OG pairing with the anti-conformation of dA. c A figure showing the extra-helical dA base that was in template-primer 8OG: dA base pair. A simulated-annealing omit map contoured at 3σ is shown in green for the extra-helical dA base. d A figure illustrating the additional bound dCMPP(CH2)P molecule forming an abortive ternary complex in the active site.
