Mutagenic bypass of the butadiene-derived 2'-deoxyuridine adducts by polymerases eta and zeta

Mutat Res. 2007 Dec 1;625(1-2):40-9. doi: 10.1016/j.mrfmmm.2007.05.003. Epub 2007 May 18.


Butadiene is a ubiquitous environmental chemical carcinogen that when activated to its monoepoxide intermediate can react with the N3 position of cytosine, resulting in two stereoisomeric adducted bases that rapidly deaminate to N3 2'-deoxyuridine lesions. We have previously shown that replication of DNAs containing these adducts through mammalian cells resulted in approximately 97% mutagenicity, predominantly C to T transitions. Since replicative DNA polymerases were blocked by these lesions in vitro, translesional polymerases were assessed for their ability to bypass these adducts. While polymerases iota, kappa and zeta were significantly blocked one nucleotide prior to the lesion, pol eta incorporated nucleotides opposite the adducts with a preference for insertion of a G or A. Following polymerase dissociation and reassociation, pol eta was also able to extend primers with mispaired termini opposite the lesions, with extensions from the A and T mismatched primer termini being the most efficient. Pol zeta was also able to extend primers containing all mismatched nucleotides opposite the lesions, with the most efficient extension occurring off of the A mismatched primer.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Base Sequence
  • Butadienes / metabolism*
  • COS Cells
  • Chlorocebus aethiops
  • DNA Adducts / chemistry
  • DNA Adducts / genetics
  • DNA Adducts / metabolism*
  • DNA Primers / genetics
  • DNA-Directed DNA Polymerase / genetics
  • DNA-Directed DNA Polymerase / metabolism*
  • Deoxyuracil Nucleotides / metabolism*
  • Humans
  • In Vitro Techniques
  • Mutagenesis
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism


  • Butadienes
  • DNA Adducts
  • DNA Primers
  • Deoxyuracil Nucleotides
  • Recombinant Proteins
  • DNA polymerase zeta
  • DNA-Directed DNA Polymerase
  • Rad30 protein