Error-free and Error-Prone Lesion Bypass by Human DNA Polymerase Kappa in Vitro

Nucleic Acids Res. 2000 Nov 1;28(21):4138-46. doi: 10.1093/nar/28.21.4138.

Abstract

Error-free lesion bypass and error-prone lesion bypass are important cellular responses to DNA damage during replication, both of which require a DNA polymerase (Pol). To identify lesion bypass DNA polymerases, we have purified human Polkappa encoded by the DINB1 gene and examined its response to damaged DNA templates. Here, we show that human Polkappa is a novel lesion bypass polymerase in vitro. Purified human Polkappa efficiently bypassed a template 8-oxoguanine, incorporating mainly A and less frequently C opposite the lesion. Human Polkappa most frequently incorporated A opposite a template abasic site. Efficient further extension required T as the next template base, and was mediated mainly by a one-nucleotide deletion mechanism. Human Polkappa was able to bypass an acetylaminofluorene-modified G in DNA, incorporating either C or T, and less efficiently A opposite the lesion. Furthermore, human Polkappa effectively bypassed a template (-)-trans-anti-benzo[a]pyrene-N:(2)-dG lesion in an error-free manner by incorporating a C opposite the bulky adduct. In contrast, human Polkappa was unable to bypass a template TT dimer or a TT (6-4) photoproduct, two of the major UV lesions. These results suggest that Polkappa plays an important role in both error-free and error-prone lesion bypass in humans.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 2-Acetylaminofluorene / pharmacology
  • Base Pair Mismatch / genetics
  • Base Sequence
  • Benzo(a)pyrene / pharmacology
  • Catalysis
  • DNA Adducts / drug effects
  • DNA Adducts / genetics
  • DNA Adducts / metabolism
  • DNA Damage / drug effects
  • DNA Damage / genetics*
  • DNA-Directed DNA Polymerase*
  • Guanine / analogs & derivatives*
  • Guanine / metabolism
  • Humans
  • Mutagenesis / drug effects
  • Mutagenesis / genetics*
  • Mutagens / pharmacology
  • Nucleotides / genetics
  • Nucleotides / metabolism
  • Proteins / genetics
  • Proteins / isolation & purification
  • Proteins / metabolism*
  • Pyrimidine Dimers / genetics
  • Pyrimidine Dimers / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / isolation & purification
  • Recombinant Fusion Proteins / metabolism
  • Substrate Specificity
  • Templates, Genetic

Substances

  • DNA Adducts
  • Mutagens
  • Nucleotides
  • Proteins
  • Pyrimidine Dimers
  • Recombinant Fusion Proteins
  • Benzo(a)pyrene
  • 8-hydroxyguanine
  • Guanine
  • 2-Acetylaminofluorene
  • DNA-Directed DNA Polymerase
  • POLK protein, human