Fig. 6: Residues experimentally determined to be critical for transfer of DNA primer strand from polymerase to exonuclease active site.
From: Polymerization and editing modes of a high-fidelity DNA polymerase are linked by a well-defined path
a–c Close up of the transition path between polymerase and exonuclease active site in (a) polymerase mode, (b) intermediate mode, and (c) exonuclease mode. Polymerase is colored in orange, exonuclease in green, template DNA strand in dark blue, and primer strand in light blue. Mutated residues are shown in dark green sticks. d Denaturing gel analysis of polymerase activity of wild type and mutant proteins on matched DNA. Mutants showing W-T activity are highlighted in green, mutations that are moderately affected in orange, and mutations that render the protein inactive in red. e Similar analysis using a DNA substrate with a terminal C–T mismatch. f Exonuclease activity on matched (C–G) and mismatched (C–T) DNA measured in the same DNA substrates as in panels d and e in the absence of nucleotides. g Overview of Pol III core complex in polymerase mode. The mutated residues are highlighted in dark green and the β-clamp in gray. The experiments in panels d, e have been reproduced more than three times, the experiment in panel f have been reproduced twice.
