NMR structure of the thrombin-binding DNA aptamer stabilized by Sr2+
NMR structure of the thrombin-binding DNA aptamer stabilized by Sr2+
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DOI：
10.1080/07391102.2004.10506977
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发表时间：
2004-08-01
影响因子：
4.4
通讯作者：
Gmeiner, WH
中科院分区：
文献类型：
--
作者：
Mao, XA;Marky, LA;Gmeiner, WH
凝血酶结合的DNA适配体与一个单一的Sr 2+离子（Sr 2+：TBA复合物）的结构已被确定使用NMR光谱和约束的分子动力学模拟。四链体结构的Sr 2+：TBA复合物是类似的拓扑结构，但不同的结构，从以前报道的K+：TBA复合物。Sr 2+：TBA复合物的四分体间距为3.8埃，或比K+：TBA复合物中的大0.7埃。这种实质性差异可归因于Sr2+：TBA复合物中Sr2+的结合位点与K+：TBA复合物中K+的结合位点不同。Sr2+：TBA络合物呈现1：1的化学计量比，并且很可能Sr 2+离子同时与两个G-四分体的八个O6原子相互作用。结果表明，四链体DNA结构对特定金属离子的存在高度敏感。特定金属离子的结合可以调节体内四链体DNA结构的生物活性。
The structure of thrombin-binding DNA aptamer complexed with a single Sr2+ ion (Sr2+:TBA complex) has been determined using NMR spectroscopy and restrained molecular dynamics simulations. The quadruplex structure for the Sr2+:TBA complex is similar in topology, but distinct in structure, from that previously reported for the K+:TBA complex. The inter-tetrad distance of the Sr2+:TBA complex is 3.8 Angstrom, or 0.7 Angstrom larger than in the K+:TBA complex. This substantial difference can be attributed to a different binding site for Sr2+ in the Sr2+:TBA complex than for K+ in the K+:TBA complex. The Sr2+:TBA complex assumes a 1: 1 stoichiometry, and it is very likely that the Sr2+ ion simultaneously interacts with the eight O6 atoms of the two G-tetrads. The results indicate that quadruplex DNA structures are highly sensitive to the presence of specific metal ions. The binding of specific metal ions may modulate the biological activity of quadruplex DNA structures in vivo.