Polymerization and editing modes of a high-fidelity DNA polymerase are linked by a well-defined path

Abstract

In high fidelity DNA polymerases the exonuclease site is distal from the polymerization site and it is unknown how the primer strand travels between the two sites when mis-incorporated nucleotides must be removed. Here, the authors perform MD simulations and identify an optimal path for DNA primer strand translocation in the E. coli replicative DNA polymerase III and characterise the kinetics and dynamics of the Pol III pol-to-exo mode transition, which is validated with mutagenesis experiments.