Reduced structural flexibility for an exonuclease deficient DNA polymerase III mutant.

ABSTRACT: DNA synthesis, carried out by DNA polymerases, requires balancing speed and accuracy for faithful replication of the genome. High fidelity DNA polymerases contain a 3'-5' exonuclease domain that can remove misincorporated nucleotides on the 3' end of the primer strand, a process called proofreading. The E. coli replicative polymerase, DNA polymerase III, has spatially separated (∼55 Å apart) polymerase and exonuclease subunits. Here, we report on the dynamics of E. coli DNA polymerase III proofreading in the presence of its processivity factor, the β2-sliding clamp, at varying base pair termini using single-molecule FRET. We find that the binding kinetics do not depend on the base identity at the termini, indicating a tolerance for DNA mismatches. Further, our single-molecule data and MD s

SUBMITTER: Gahlon HL 

PROVIDER: S-EPMC6278910 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature