RNA LEGO : Construction of functional RNA nanostructures

我们以前已经表明，RNA底物组成的两个茎环连接一个短的接头，可用于构建特定的环状或线性自组装通过环-环相互作用。我们还表明，通过调节环-环相互作用的强度，可以以镁依赖性方式控制RNA结构的组装和分解（Horiya等人，化学和生物学：2003).在本项目期间，我们获得了以下结果：1）我们表明由三个茎-环组成的RNA底物可用于构建树状聚合物组装体（Fujiya和Harada，Nucleic Acids Symp.Ser.，2）我们证明了环状和线性RNA组装体之间的相互转化可以通过外部底物如镁离子来调节（Ohmori等人，核酸合成系列，3）我们表明，环状RNA组装体可以有效地异构化为化学稳定的结构。使用这种结构异构化作为功能开关，设计了通过环-环相互作用组装成环状二聚体并异构化以形成肽结合位点和催化结构域的RNA底物（Li等人，美国化学学会，2006）。4）我们表明热异构化可以用作构建复杂纳米结构的开关。这是通过设计RNA环-环复合物来实现的，所述RNA环-环复合物在热异构化后形成彼此互补的5 '和3'单链区域。这样的基底可用于形成线性和二维组件（Kunimoto等人，正在筹备中）。

We have previously shown that RNA substrates consisting of two stem-loops connected by a short linker can be used to construct specific circular or linear self-assemblies through loop-loop interactions. We also showed that by adjusting the strength of the loop-loop interaction, the assembly and disassembly of the RNA structures could be controlled in a magnesium-dependent manner (Horiya et al., Chem.＆ Biol., 2003).During this project term, we obtained the following results:1) We showed that RNA substrates consisting of three stem-loops could be used to construct dendrimeric assemblies (Fujiya and Harada, Nucleic Acids Symp.Ser., 2004).2) We demonstrated that the interconversion between circular and linear RNA assemblies could be regulated by an external substrate such as magnesium ion (Ohmori et al., Nucleic Acids Symp.Ser., 2005).3) We showed that circular RNA assemblies can be efficiently isomerized to a thermodynamically stable structure. Using this structural isomerization as a functional switch, RNA substrates that assemble into circular dimers through loop-loop interactions, and isomerizes to form peptide binding sites and catalytic domains were designed (Li et al., J.Am.Chem.Soc., 2006).4) We showed that thermal isomerization can be used as a switch to construct complex nanostructures. This was accomplished by designing RNA loop-loop complexes that upon thermal isomerization form 5'- and 3'-single stranded regions complementary to each other. Such substrates can be used to form linear and two-dimensional assemblies (Kunimoto et al., in preparation).