A Novel AgI-DNA Rod Comprising a One-Dimensional Array of 11 Silver Ions within a Double Helical Structure

DNA/RNA duplexes containing metal-ion-mediated base pairs (metallo-base pairs) have potential applications in developing nucleic acid-based nanodevices and genetic code expansion. Many metallo-base pairs are formed within duplexes stabilized by Watson-Crick base pairs. Recently, the crystal structure of an Ag-I-DNA nanowire with an uninterrupted one-dimensional silver array was determined. Here, we present a new DNA helical wire, the Ag-I-DNA rod, containing an uninterrupted array of 11 Ag-I ions. The Ag-I-DNA rod consisted of only C-Ag-I-C, G-Ag-I-G, G-Ag-I-5-bromouracil (U-Br), and U-Br-Ag-I-U-Br metallo base pairs, with no Watson-Crick pairs. The Ag-I-DNA rods were connected by non-canonical G-G pairs in crystals. Notably, data from our absorbance, circular dichroism, nuclear magnetic resonance, and mass spectrometry analyses suggested that the Ag-I-DNA rods formed in solution, as well as within crystals.

Automated summary

DNA/RNA duplexes can contain metal-ion-mediated base pairs, which have potential applications in nanodevices and genetic code expansion. Recently, a crystal structure of an Ag-I-DNA nanowire with a continuous one-dimensional silver array was determined. In addition, a new DNA helical wire called the Ag-I-DNA rod, consisting of an uninterrupted array of 11 Ag-I ions, was presented.