CRUK Biomolecular Structure Group, The School of Pharmacy, University of London, WC1N 1AX London, United Kingdom.
J Am Chem Soc. 2010 Jul 14;132(27):9328-34. doi: 10.1021/ja100345z.
We report on the self-assembled structures formed by 12-mer, 22-mer, and 45-mer telomeric RNA (telRNA/TERRA) sequences compared to their DNA analogues, as studied by electrospray mass spectrometry, circular dichroism, and thermal denaturation. The major difference between telomeric RNA and DNA sequences is the ability of telomeric RNA to form higher-order dimeric assemblies, initiated by cation-mediated stacking of two parallel G-quadruplex subunits. The 5'-5' stacking had been observed recently by NMR for the r(GGGUUAGGGU) 10-mer (Martadinata, H.; Phan, A. T. J. Am. Chem. Soc. 2009, 131, 2570); the present work shows that stacking also occurs for the 22-mer containing four G-tracts and for the 45-mer containing eight G-tracts, suggesting a general structural feature of telomeric RNA. The importance of kinetic effects in multimer formation, unfolding, and structural rearrangements is also highlighted.
我们报告了 12 聚体、22 聚体和 45 聚体端粒 RNA（telRNA/TERRA）序列与其 DNA 类似物形成的自组装结构，通过电喷雾质谱、圆二色性和热变性研究。端粒 RNA 与 DNA 序列的主要区别在于端粒 RNA 能够形成更高阶的二聚体组装，这是由两个平行的 G-四链体亚基的阳离子介导堆积引发的。最近通过 NMR 观察到了 r(GGGUUAGGGU) 10 聚体的 5'-5'堆积（Martadinata，H.；Phan，A. T. J. Am. Chem. Soc. 2009，131，2570）；本工作表明，含有四个 G 链段的 22 聚体和含有八个 G 链段的 45 聚体也发生了堆积，这表明了端粒 RNA 的一般结构特征。多聚体形成、解折叠和结构重排中动力学效应的重要性也得到了强调。
