RNA LEGO : Construction of functional RNA nanostructures

我们之前已经证明，RNA底物由两个茎环组成，通过短连接器连接，可以通过环环相互作用构建特定的圆形或线性自组装。我们还表明，通过调节环环相互作用的强度，RNA结构的组装和拆卸可以以镁依赖的方式控制(Horiya等人，化学。和杂志。, 2003)。在这个项目期间，我们获得了以下结果：1)我们发现由三个茎环组成的RNA底物可以用来构建树突细胞组装(Fujiya和Harada，核酸symps . ser；, 2004)。2)我们证明了环状和线性RNA组件之间的相互转换可以通过外部底物如镁离子来调节(Ohmori等人，核酸症状。, 2005)。3)我们发现环状RNA组装可以有效地异构化成一个热力学稳定的结构。利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的RNA底物，并通过异构化形成肽结合位点和催化结构域（Li et al., j.am chem . soc .）。, 2006)。4)我们发现热异构化可以作为一种开关来构建复杂的纳米结构。这是通过设计RNA环环复合物来完成的，这些环环复合物在热异构化后形成相互互补的5‘和3’单链区域。这种衬底可用于形成线性和二维组件（Kunimoto等人，在制备中）。

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).