Numerous applications of metal‐mediated base pairs (metallo‐base‐pairs) to nucleic acid based nanodevices and genetic code expansion have been extensively studied. Many of these metallo‐base‐pairs are formed in DNA and RNA duplexes containing Watson–Crick base pairs. Recently, a crystal structure of a metal–DNA nanowire with an uninterrupted one‐dimensional silver array was reported. We now report the crystal structure of a novel DNA helical wire containing HgII‐mediated T:T and T:G base pairs and water‐mediated C:C base pairs. The Hg‐DNA wire does not contain any Watson–Crick base pairs. Crystals of the Hg‐DNA wire, which is the first DNA wire structure driven by HgII ions, were obtained by mixing the short oligonucleotide d(TTTGC) and HgII ions. This study demonstrates the potential of metallo‐DNA to form various structural components that can be used for functional nanodevices.

Numerous applications of metal-mediated base pairs (metallo-base-pairs) to nucleic acid based nanodevices and genetic code expansion have been extensively studied. Many of these metallo-base-pairs are formed in DNAa nd RNA duplexes containing Watson-Crick base pairs.Recently,acrystal structure of am etal-DNAnanowire with an uninterrupted one-dimensional silver arraywas reported. We nowreport the crystal structure of anovel DNAhelical wire containing Hg IImediated T:Tand T:Gbase pairs and water-mediated C:Cbase pairs.T he Hg-DNAwire does not contain any Watson-Crick base pairs.C rystals of the Hg-DNAw ire,w hich is the first DNAw ire structure driven by Hg II ions,w ere obtained by mixing the short oligonucleotide d(TTTGC) and Hg II ions. This study demonstrates the potential of metallo-DNAtoform various structural components that can be used for functional nanodevices.

The crystal structure of a DNA duplex cross-linked by 6-thioguanine–6-thioguanine disulfides has been solved.