Kinetics of error detection in homologous B-family DNA polymerases

• Author(s) / Creator(s)

  • Cooper, W.
  • Hogg, M.
  • Reha-Krantz, L.
  • Wallace, S.S.

• The kinetics of forming a proper Watson–Crick base pair as well incorporating bases opposite furan, an abasic site analog, have been well characterized for the B Family replicative DNA polymerase from bacteriophage T4. Structural studies of these reactions, however, have only been performed with the homologous enzyme from bacteriophage RB69. In this work, the homologous enzymes from RB69 and T4 were compared in parallel reactions to determine the relative abilities of the two polymerases to incorporate correct nucleotides as well as to form improper pairings. The kinetic rates for three different exonuclease mutants for each enzyme were measured for incorporation of an A opposite T and an A opposite furan as well as for the formation of A:C and T:T mismatches. The T4 exonuclease mutants were all ~2- to 7-fold more efficient than the corresponding RB69 exonuclease mutants depending on whether a T or furan was in the templating position and which exonuclease mutant was used. The rates for mismatch formation by T4 were significantly reduced compared with incorporation opposite furan,much more so than the corresponding RB69 mutant. These results show that there are kinetic differences between the two enzymes but they are not large enough to preclude structural assumptions for T4DNApolymerase based on the known structure of the RB69 DNA polymerase.

• Date created

  2006

• Subjects / Keywords

  • Bateriophage-T4
  • Spontaneous mutation
  • Crystal-structure
  • Abasic sites
  • Nucleotide incorporation
  • Replication fidelity
  • Complex
  • Acid
  • In-vitro
  • Exonuclease

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/R3N00ZW6W

• License

  © The Author 2006. Published by Oxford University Press. All rights reserved. The online version of this article has been published under an open access model. Users are entitled to use, reproduce, disseminate, or display the open access version of this article for non-commercial purposes provided that: the original authorship is properly and fully attributed; the Journal and Oxford University Press are attributed as the original place of publication with the correct citation details given; if an article is subsequently reproduced or disseminated not in its entirety but only in part or as a derivative work this must be clearly indicated. For commercial re-use, please contact journals.permissions@oxfordjournals.org