DNA oligonucleotides with A, T, G or C opposite an abasic site: structure and dynamics.

Abasic sites are common DNA lesions resulting from spontaneous depurination and excision of damaged nucleobases by DNA repair enzymes. However, the influence of the local sequence context on the structure of the abasic site and ultimately, its recognition and repair, remains elusive. In the present study, duplex DNAs with three different bases (G, C or T) opposite an abasic site have been synthesized in the same sequence context (5'-CCA AAG6 XA8C CGG G-3', where X denotes the abasic site) and characterized by 2D NMR spectroscopy.