Regulated Incorporation of Two Different Metal Ions into Programmed Sites in a Duplex by DNA Polymerase Catalyzed Primer Extension

Metal-mediated base pairs formed by the coordination of metal ions to natural or artificial bases impart unique chemical and physical properties to nucleic acids and have attracted considerable interest in the field of nanodevices. Ag-I ions were found to mediate DNA polymerase catalyzed primer extension through the formation of a C-Ag-I-T base pair, as well as the previously reported C-Ag-I-A base pair. The comparative susceptibility of dNTPs to Ag-I-mediated enzymatic incorporation into the site opposite cytosine in the template was shown to be dATP > dTTP >> dCTP. Furthermore, two kinds of metal ions, Ag-I and Hg-II, selectively mediate the incorporation of thymidine 5'-triphosphate into sites opposite cytosine and thymine in the template, respectively. In other words, the regulated incorporation of different metal ions into programmed sites in the duplex by DNA polymerase was successfully achieved.