A robust DNA mechanical device controlled by hybridization topology
A robust DNA mechanical device controlled by hybridization topology
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DOI：
10.1038/415062a
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发表时间：
2002-01-03
期刊：
影响因子：
64.8
通讯作者：
Seeman, NC
中科院分区：
文献类型：
--
作者：
Yan, H;Zhang, XP;Seeman, NC
通过利用氧化还原电位或温度变化、小分子或离子的可逆结合或辐射所引发的构象变化，分子级装置中的受控机械运动已在多种系统中实现，例如链烯和轮烷(1-3)、手性分子开关(4)、分子棘轮(5)和DNA(6)。原则上，将此类设备合并到阵列（7,8）中可以产生适合纳米机器人应用的复杂结构状态，前提是可以单独寻址各个设备。但由于常用的触发器往往在所有存在的设备上作用相同，因此需要非常严格地本地化它们。这可以通过由单独的设备专用试剂单独控制的设备轻松实现。允许这种特定控制的触发机制是 DNA 链的可逆结合，从而“促进”DNA 机器中的构象变化 (9)。在这里，我们通过演示以四步循环运行的稳健的序列依赖性旋转 DNA 装置，改进了使用该机制但产生副产品 (9) 的初始原型系统。我们证明，DNA 链通过诱导两个强大的拓扑基序（平行交叉 (PX) DNA(10,11) 及其拓扑异构体 JX(2) DNA）之间的相互转换来控制和推动我们的设备循环，其中一条链末端相对于另一条链旋转 180 度。我们期望通过改变控制链和它们结合的装置序列可以创建各种类似但不同的旋转装置。
Controlled mechanical movement in molecular-scale devices has been realized in a variety of systems-catenanes and rotaxanes(1-3), chiroptical molecular switches(4), molecular ratchets(5) and DNA(6)- by exploiting conformational changes triggered by changes in redox potential or temperature, reversible binding of small molecules or ions, or irradiation. The incorporation of such devices into arrays(7,8) could in principle lead to complex structural states suitable for nanorobotic applications, provided that individual devices can be addressed separately. But because the triggers commonly used tend to act equally on all the devices that are present, they will need to be localized very tightly. This could be readily achieved with devices that are controlled individually by separate and device-specific reagents. A trigger mechanism that allows such specific control is the reversible binding of DNA strands, thereby 'fuelling' conformational changes in a DNA machine(9). Here we improve upon the initial prototype system that uses this mechanism but generates by-products(9), by demonstrating a robust sequence-dependent rotary DNA device operating in a four-step cycle. We show that DNA strands control and fuel our device cycle by inducing the interconversion between two robust topological motifs, paranemic crossover (PX) DNA(10,11) and its topoisomer JX(2) DNA, in which one strand end is rotated relative to the other by 180 degrees. We expect that a wide range of analogous yet distinct rotary devices can be created by changing the control strands and the device sequences to which they bind.