A Nanostructure Made of a Bacterial Noncoding RNA
A Nanostructure Made of a Bacterial Noncoding RNA
复制标题
DOI：
10.1021/ja906076e
复制
发表时间：
2009-12-02
影响因子：
15
通讯作者：
Isambert, Herve
中科院分区：
文献类型：
--
作者：
Cayrol, Bastien;Nogues, Claude;Isambert, Herve
与许多蛋白质不同，天然RNA尽管具有多种细胞功能，但从未有报道称其能形成扩展的纳米结构。这一点更加令人惊讶，因为长期以来人们已经成功设计出能形成大型纳米结构的合成DNA和RNA。在此，我们表明，大肠杆菌的一种87个核苷酸的非编码RNA——DsrA，通过三个连续的自身互补区域的反义相互作用自组装成一系列纳米结构。然而，利用原子力显微镜（AFM）和荧光显微镜观察到的这些扩展的纳米结构很容易被分解成长度大于100纳米的DsrA细丝螺旋束，其中包含数百个DsrA单体，并且令人惊讶的是，它们对热和尿素变性具有抗性。分子建模表明，DsrA纳米结构向细丝束的这种结构转变是由于储存的扭转约束的松弛，并暗示了其对DsrA调节功能可能产生的影响。
Natural RNAs, unlike many proteins, have never been reported to form extended nanostructures, despite their wide variety of cellular functions. This is all the more striking, as synthetic DNA and RNA forming large nanostructures have long been successfully designed. Here, we show that DsrA, a 87-nt noncoding RNA of Escherishia coli, self-assembles into a hierarchy of nanostructures through antisense interactions of three contiguous self-complementary regions. Yet, the extended nanostructures, observed using atomic force microscopy (AFM) and fluorescence-microscopy, are easily disrupted into >100 nm long helical bundles of DsrA filaments, including hundreds of DsrA monomers, and are surprisingly resistant to heat and urea denaturation. Molecular modeling demonstrates that this structural switch of DsrA nanostructures into filament bundles results from the relaxation of stored torsional constraints and suggests possible implications for DsrA regulatory function.