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Dynamics of Proofreading by the E. coli Pol III Replicase

Journal Article


Abstract


  • The αεθ core of Escherichia coli DNA polymerase III (Pol III) associates with the β 2 sliding clamp to processively synthesize DNA and remove misincorporated nucleotides. The α subunit is the polymerase while ε is the 3' to 5' proofreading exonuclease. In contrast to the polymerase activity of Pol III, dynamic features of proofreading are poorly understood. We used single-molecule assays to determine the excision rate and processivity of the β 2 -associated Pol III core, and observed that both properties are enhanced by mutational strengthening of the interaction between ε and β 2 . Thus, the ε-β 2 contact is maintained in both the synthesis and proofreading modes. Remarkably, single-molecule real-time fluorescence imaging revealed the dynamics of transfer of primer-template DNA between the polymerase and proofreading sites, showing that it does not involve breaking of the physical interaction between ε and β 2 .

Authors


  •   Park, Jonghyun (external author)
  •   Jergic, Slobodan
  •   Jeon, Yongmoon (external author)
  •   Cho, Won-Ki (external author)
  •   Lee, Ryanggeun (external author)
  •   Dixon, Nicholas E.
  •   Lee, Jong-Bong (external author)

Publication Date


  • 2018

Citation


  • Park, J., Jergic, S., Jeon, Y., Cho, W., Lee, R., Dixon, N. E. & Lee, J. (2018). Dynamics of Proofreading by the E. coli Pol III Replicase. Cell Chemical Biology, 25 (1), 57-66.

Scopus Eid


  • 2-s2.0-85035055424

Ro Metadata Url


  • http://ro.uow.edu.au/ihmri/1201

Number Of Pages


  • 9

Start Page


  • 57

End Page


  • 66

Volume


  • 25

Issue


  • 1

Place Of Publication


  • United States

Abstract


  • The αεθ core of Escherichia coli DNA polymerase III (Pol III) associates with the β 2 sliding clamp to processively synthesize DNA and remove misincorporated nucleotides. The α subunit is the polymerase while ε is the 3' to 5' proofreading exonuclease. In contrast to the polymerase activity of Pol III, dynamic features of proofreading are poorly understood. We used single-molecule assays to determine the excision rate and processivity of the β 2 -associated Pol III core, and observed that both properties are enhanced by mutational strengthening of the interaction between ε and β 2 . Thus, the ε-β 2 contact is maintained in both the synthesis and proofreading modes. Remarkably, single-molecule real-time fluorescence imaging revealed the dynamics of transfer of primer-template DNA between the polymerase and proofreading sites, showing that it does not involve breaking of the physical interaction between ε and β 2 .

Authors


  •   Park, Jonghyun (external author)
  •   Jergic, Slobodan
  •   Jeon, Yongmoon (external author)
  •   Cho, Won-Ki (external author)
  •   Lee, Ryanggeun (external author)
  •   Dixon, Nicholas E.
  •   Lee, Jong-Bong (external author)

Publication Date


  • 2018

Citation


  • Park, J., Jergic, S., Jeon, Y., Cho, W., Lee, R., Dixon, N. E. & Lee, J. (2018). Dynamics of Proofreading by the E. coli Pol III Replicase. Cell Chemical Biology, 25 (1), 57-66.

Scopus Eid


  • 2-s2.0-85035055424

Ro Metadata Url


  • http://ro.uow.edu.au/ihmri/1201

Number Of Pages


  • 9

Start Page


  • 57

End Page


  • 66

Volume


  • 25

Issue


  • 1

Place Of Publication


  • United States