Base-pairing properties of the oxidized cytosine derivative, 5-hydroxy uracil

Varatharasa Thiviyanathan, Anoma Somasunderam, David E. Volk, Tapas K. Hazra, Sankar Mitra, David G. Gorenstein

Research output: Contribution to journalArticle

35 Scopus citations

Abstract

The most abundant base-substitution mutation resulting from oxidative damage to DNA is the GC to AT transition mutation. 5-hydroxyuracil (5-OHU), produced by the oxidative deamination of cystosine, has been established as the major chemical precursor for this most abundant transition mutation. Results from NMR spectroscopy and UV melting experiments show that 5-OHU would form the most stable pair with G, and the least stable pair with C. The hydroxyl group in the 5th position of the 5-OHU residue may play a role in increasing the stability of the 5-OHU:G pair over the normal Watson-Crick pair, the 5-OHU:A. The 5-OHU:C base pair would be least stable, and would destabilize the base-stacking in the duplex. Our results explain why certain DNA polymerases preferentially incorporate G opposite to 5-OHU over A and why C does not get incorporated against 5-OHU during DNA replication in vivo.

Original languageEnglish (US)
Pages (from-to)752-757
Number of pages6
JournalBiochemical and Biophysical Research Communications
Volume366
Issue number3
DOIs
StatePublished - Feb 15 2008
Externally publishedYes

    Fingerprint

Keywords

  • Base-pair mismatch
  • DNA repair
  • Hydroxy uracil
  • Oxidative DNA damage

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this