Switching between polymerase and exonuclease sites in DNA polymerase ε.

ABSTRACT: The balance between exonuclease and polymerase activities promotes DNA synthesis over degradation when nucleotides are correctly added to the new strand by replicative B-family polymerases. Misincorporations shift the balance toward the exonuclease site, and the balance tips back in favor of DNA synthesis when the incorrect nucleotides have been removed. Most B-family DNA polymerases have an extended β-hairpin loop that appears to be important for switching from the exonuclease site to the polymerase site, a process that affects fidelity of the DNA polymerase. Here, we show that DNA polymerase ε can switch between the polymerase site and exonuclease site in a processive manner despite the absence of an extended β-hairpin loop. K967 and R988 are two conserved amino acids in the palm and thu

SUBMITTER: Ganai RA 

PROVIDER: S-EPMC4333401 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature