| Literature DB >> 18078807 |
Varatharasa Thiviyanathan1, Anoma Somasunderam, David E Volk, Tapas K Hazra, Sankar Mitra, David G Gorenstein.
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.Entities:
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Year: 2007 PMID： 18078807 PMCID： PMC2262052 DOI： 10.1016/j.bbrc.2007.12.010
Source DB: PubMed Journal: Biochem Biophys Res Commun ISSN： 0006-291X Impact factor: 3.575