Observing translesion synthesis of an aromatic amine DNA adduct by a high-fidelity DNA polymerase.

Published

Journal Article

Aromatic amines have been studied for more than a half-century as model carcinogens representing a class of chemicals that form bulky adducts to the C8 position of guanine in DNA. Among these guanine adducts, the N-(2'-deoxyguanosin-8-yl)-aminofluorene (G-AF) and N-2-(2'-deoxyguanosin-8-yl)-acetylaminofluorene (G-AAF) derivatives are the best studied. Although G-AF and G-AAF differ by only an acetyl group, they exert different effects on DNA replication by replicative and high-fidelity DNA polymerases. Translesion synthesis of G-AF is achieved with high-fidelity polymerases, whereas replication of G-AAF requires specialized bypass polymerases. Here we have presented structures of G-AF as it undergoes one round of accurate replication by a high-fidelity DNA polymerase. Nucleotide incorporation opposite G-AF is achieved in solution and in the crystal, revealing how the polymerase accommodates and replicates past G-AF, but not G-AAF. Like an unmodified guanine, G-AF adopts a conformation that allows it to form Watson-Crick hydrogen bonds with an opposing cytosine that results in protrusion of the bulky fluorene moiety into the major groove. Although incorporation opposite G-AF is observed, the C:G-AF base pair induces distortions to the polymerase active site that slow translesion synthesis.

Full Text

Duke Authors

Cited Authors

  • Hsu, GW; Kiefer, JR; Burnouf, D; Becherel, OJ; Fuchs, RPP; Beese, LS

Published Date

  • November 26, 2004

Published In

Volume / Issue

  • 279 / 48

Start / End Page

  • 50280 - 50285

PubMed ID

  • 15385534

Pubmed Central ID

  • 15385534

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.M409224200

Language

  • eng

Conference Location

  • United States