1CFL

DNA DECAMER DUPLEX CONTAINING T5-T6 PHOTOADDUCT

Summary for 1CFL

• Entry DOI: 10.2210/pdb1cfl/pdb
• NMR Information: BMRB: 4488
• Descriptor: DNA (5'-D(*CP*GP*CP*AP*(64T)P*TP*AP*CP*GP*C)-3'), DNA (5'-D(*GP*CP*GP*TP*GP*AP*TP*GP*CP*G)-3') (2 entities in total)
• Functional Keywords: dna photoproduct, (6-4) adduct, mutagenesis, deoxyribonucleic acid, dna
• Total number of polymer chains: 2
• Total formula weight: 6124.02

Authors

Lee, J.-H.,Hwang, G.-S.,Choi, B.-S. (deposition date: 1999-03-19, release date: 1999-05-28, Last modification date: 2023-12-27)

Primary citation

Lee, J.H.,Hwang, G.S.,Choi, B.S.
Solution structure of a DNA decamer duplex containing the stable 3' T.G base pair of the pyrimidine(6-4)pyrimidone photoproduct [(6-4) adduct]: implications for the highly specific 3' T --> C transition of the (6-4) adduct.
Proc.Natl.Acad.Sci.USA, 96:6632-6636, 1999

PubMed Abstract: The pyrimidine(6-4)pyrimidone photoproduct [(6-4) adduct] is one of the major photoproducts induced by UV irradiation of DNA and occurs at TpT sites. The (6-4) adduct is highly mutagenic and leads most often to a 3' T --> C transition with 85% replicating error frequency [LeClerc, J. E., Borden, A. & Lawrence, C. W. (1991) Proc. Natl. Acad. Sci. USA 88, 9685-9689]. To determine the origin of the specific 3' T --> C transition of the (6-4) adduct, we have used experimental NMR restraints and molecular dynamics to determine the solution structure of a (6-4)-lesion DNA decamer duplex that contains a mismatched base pair between the 3' T residue and an opposed G residue. Normal Watson-Crick-type hydrogen bonding is retained at the 5' T of the lesion site. The O2 carbonyl of the 3' T residue forms hydrogen bonds with the imino and amino protons of the opposed G residue. This potential hydrogen bonding stabilizes the overall helix and restores the highly distorted conformation of the (6-4) adduct to the typical B-form-like DNA structure. This structural feature can explain the marked preference for the insertion of an A residue opposite the 5' T and a G residue opposite the 3' T of the (6-4) lesion during trans-lesion synthesis. Thus these insertions yield the predominant 3' T --> C transition.

PubMed: 10359763
DOI: 10.1073/pnas.96.12.6632

Experimental method

SOLUTION NMR