Yamaguchi Hiroshi, Sebera Jakub, Kondo Jiro, Oda Shuji, Komuro Tomoyuki, Kawamura Takuya, Dairaku Takenori, Kondo Yoshinori, Okamoto Itaru, Ono Akira, Burda Jaroslav V, Kojima Chojiro, Sychrovský Vladimír, Tanaka Yoshiyuki
Laboratory of Molecular Transformation, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10, Praha 6, Czech Republic, Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyoda-ku, Tokyo 102-8554, Japan, Department of Material and Life Chemistry, Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama, Kanagawa 221-8686 Japan, Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 121 16 Prague 2, Czech Republic and Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Nucleic Acids Res. 2014 Apr;42(6):4094-9. doi: 10.1093/nar/gkt1344. Epub 2013 Dec 26.
We have determined the three-dimensional (3D) structure of DNA duplex that includes tandem Hg(II)-mediated T-T base pairs (thymine-Hg(II)-thymine, T-Hg(II)-T) with NMR spectroscopy in solution. This is the first 3D structure of metallo-DNA (covalently metallated DNA) composed exclusively of 'NATURAL' bases. The T-Hg(II)-T base pairs whose chemical structure was determined with the (15)N NMR spectroscopy were well accommodated in a B-form double helix, mimicking normal Watson-Crick base pairs. The Hg atoms aligned along DNA helical axis were shielded from the bulk water. The complete dehydration of Hg atoms inside DNA explained the positive reaction entropy (ΔS) for the T-Hg(II)-T base pair formation. The positive ΔS value arises owing to the Hg(II) dehydration, which was approved with the 3D structure. The 3D structure explained extraordinary affinity of thymine towards Hg(II) and revealed arrangement of T-Hg(II)-T base pairs in metallo-DNA.
我们已通过溶液中的核磁共振光谱法确定了包含串联汞（II）介导的T-T碱基对（胸腺嘧啶-汞（II）-胸腺嘧啶，T-Hg（II）-T）的DNA双链体的三维（3D）结构。这是首个完全由“天然”碱基组成的金属化DNA（共价金属化DNA）的3D结构。通过（15）N核磁共振光谱法确定化学结构的T-Hg（II）-T碱基对很好地容纳在B型双螺旋中，模仿了正常的沃森-克里克碱基对。沿DNA螺旋轴排列的汞原子被与大量水分子隔开。DNA内部汞原子的完全脱水解释了T-Hg（II）-T碱基对形成时的正反应熵（ΔS）。正ΔS值是由于汞（II）脱水产生的，这在3D结构中得到了证实。该3D结构解释了胸腺嘧啶对汞（II）的非凡亲和力，并揭示了金属化DNA中T-Hg（II）-T碱基对的排列方式。
