1UA1

Structure of aminofluorene adduct paired opposite cytosine at the polymerase active site.

Summary for 1UA1

• Entry DOI: 10.2210/pdb1ua1/pdb
• Related: 1UA0
• Descriptor: DNA primer strand, DNA template strand with aminofluorene adduct, DNA polymerase I, ... (6 entities in total)
• Functional Keywords: dna polymerase i; dna replication; klenow fragment; protein-dna complex; aminofluorene; aromatic amine; dna lesion; translation replication, transferase-dna complex, transferase/dna
• Biological source: Geobacillus stearothermophilus
• Total number of polymer chains: 3
• Total formula weight: 74199.14

Authors

Hsu, G.W.,Kiefer, J.R.,Becherel, O.J.,Fuchs, R.P.P.,Beese, L.S. (deposition date: 2004-08-11, release date: 2004-09-28, Last modification date: 2024-02-14)

Primary citation

Hsu, G.W.,Kiefer, J.R.,Becherel, O.J.,Fuchs, R.P.P.,Beese, L.S.
Observing translesion synthesis of an aromatic amine DNA adduct by a high-fidelity DNA polymerase
J.Biol.Chem., 279:50280-50285, 2004

PubMed Abstract: 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.

PubMed: 15385534
DOI: 10.1074/jbc.M409224200

Experimental method

X-RAY DIFFRACTION (2 Å)