Human DNA polymerases catalyze lesion bypass across benzo[a]pyrene-derived DNA adduct clustered with an abasic site

Lidia V. Starostenko, Nadejda I. Rechkunova, Natalia A. Lebedeva, Alexander Kolbanovskiy, Nicholas E. Geacintov, Olga I. Lavrik

Research output: Contribution to journalArticlepeer-review


The combined action of oxidative stress and genotoxic polycyclic aromatic hydrocarbons derivatives can lead to cluster-type DNA damage that includes both a modified nucleotide and a bulky lesion. As an example, we investigated the possibility of repair of an AP site located opposite a minor groove-positioned (+)-trans-BPDE-dG or a base-displaced intercalated (+)-cis-BPDE-dG adduct (BP lesion) by a BER system. Oligonucleotides with single uracil residue in the certain position were annealed with complementary oligonucleotides bearing either a cis- or trans-BP adduct. Digestion with uracil DNA glycosylase was utilized to generate an AP site which was then hydrolyzed by APE1, and the resulting gap was processed by X-family DNA polymerases β (Polβ) and λ (Polλ), or Y-family polymerase β (Polβ). By varying reaction conditions, namely, Mg2+/Mn2+ replacement/combination and ionic strength decrease, we found that under certain conditions both Polβ and Polι can catalyze lesion bypass across both cis- and trans-BP adducts in the presence of physiological dNTP concentrations. Polβ and Polι catalyze gap filling trans-lesion synthesis in an error prone manner. By contrast, Polλ selectively introduced the correct dCTP opposite the modified dG in the case of cis-BP-dG adduct only, and did not bypass the stereoisomeric trans-adduct under any of the conditions examined. The results suggest that Polλ is a specialized polymerase that can process these kinds of lesions.

Original languageEnglish (US)
Pages (from-to)1-9
Number of pages9
JournalDNA Repair
StatePublished - Dec 1 2014


  • Base excision repair
  • Benzo[a]pyrene
  • DNA polymerases
  • Lesion bypass

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


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