Solution structure of a DNA double helix with consecutive metal-mediated base pairs
Solution structure of a DNA double helix with consecutive metal-mediated base pairs
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DOI：
10.1038/nchem.512
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发表时间：
2010-03-01
期刊：
影响因子：
21.8
通讯作者：
Mueller, Jens
中科院分区：
文献类型：
--
作者：
Johannsen, Silke;Megger, Nicole;Mueller, Jens
金属介导的碱基对代表了用金属离子对核酸进行位点特异性功能化的有力工具。金属修饰的核酸的应用的发展将取决于这些双螺旋结构信息的可用性。我们在这里提出的NMR溶液结构的自我互补的DNA寡核苷酸与三个连续的咪唑核苷酸在其中心。在不存在过渡金属离子的情况下，采用发夹结构，人工核苷酸形成环。在Ag（I）离子存在下，形成包含三个咪唑-Ag +-咪唑碱基对的双链体。金属介导的碱基对形成的直接证据来自（1）N-15标记咪唑掺入后的J（N-15，Ag-107/109）偶联。双链体采用B型构象，在人工碱基区域中只有微小的偏差。这项工作代表了金属修饰的核酸与金属介导的碱基对的连续延伸的第一个结构表征。
Metal-mediated base pairs represent a powerful tool for the site-specific functionlization of nucleic acids with metal ions. The development of applications of the metal-modified nucleic acids will depend on the availability of structural information on these double helices. We present here the NMR solution structure of a self-complementary DNA oligonucleotide with three consecutive imidazole nucleotides in its centre. In the absence of transition-metal ions, a hairpin structure is adopted with the artifical nucleotides forming the loop. In the presence of Ag(I) ions, a duplex comprising three imidazole-Ag+-imidazole base pairs is formed. Direct proof for the formation of metal-mediated base pairs was obtained from (1)J(N-15,Ag-107/109) couplings upon incorporation of N-15-labelled imidazole. The duplex adopts a B-type conformation with only minor deviations in the region of the artifical bases. This work represents the first structural characterization of a metal-modified nucleic acid with a continuous stretch of metal-mediated base pairs.