Switching between Exonucleolysis and Replication by T7 DNA Polymerase Ensures High Fidelity.

ABSTRACT: DNA polymerase catalyzes the accurate transfer of genetic information from one generation to the next, and thus it is vitally important for replication to be faithful. DNA polymerase fulfills the strict requirements for fidelity by a combination of mechanisms: 1) high selectivity for correct nucleotide incorporation, 2) a slowing down of the replication rate after misincorporation, and 3) proofreading by excision of misincorporated bases. To elucidate the kinetic interplay between replication and proofreading, we used high-resolution optical tweezers to probe how DNA-duplex stability affects replication by bacteriophage T7 DNA polymerase. Our data show highly irregular replication dynamics, with frequent pauses and direction reversals as the polymerase cycles through the states that govern

SUBMITTER: Hoekstra TP 

PROVIDER: S-EPMC5340169 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature