Substrate specificity and proposed structure of the proofreading complex of T7 DNA polymerase.

ABSTRACT: Faithful replication of genomic DNA by high-fidelity DNA polymerases is crucial for the survival of most living organisms. While high-fidelity DNA polymerases favor canonical base pairs over mismatches by a factor of ∼1 × 10⁵, fidelity is further enhanced several orders of magnitude by a 3'-5' proofreading exonuclease that selectively removes mispaired bases in the primer strand. Despite the importance of proofreading to maintaining genome stability, it remains much less studied than the fidelity mechanisms employed at the polymerase active site. Here we characterize the substrate specificity for the proofreading exonuclease of a high-fidelity DNA polymerase by investigating the proofreading kinetics on various DNA substrates. The contribution of the exonuclease to net fidelity

SUBMITTER: Dangerfield TL 

PROVIDER: S-EPMC8867116 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature