Comparison between CUUG and UUCG tetraloops: thermodynamic stability and structural features analyzed by UV absorption and vibrational spectroscopy
Comparison between CUUG and UUCG tetraloops: thermodynamic stability and structural features analyzed by UV absorption and vibrational spectroscopy
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DOI：
10.1093/nar/29.19.4089
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发表时间：
2001-10-01
影响因子：
14.9
通讯作者：
Ghomi, M
中科院分区：
文献类型：
--
作者：
Baumruk, V;Gouyette, C;Ghomi, M
CUUG环是细菌16 SrRNA中最常见的四环之一。该四环具有较高的热力学稳定性，如先前的UV吸收和NMR实验所证明的。在此，我们利用多种光学技术（紫外、红外吸收、拉曼散射），研究了10聚体5 ' -r（GCG-CUUG-CGC）-3 '在水溶液中形成高度稳定的CUUG四环发夹结构的热力学和结构特征。该十聚体的UV熔融曲线提供了高熔融温度（60.7 ℃）。在不同温度下记录的一组拉曼光谱使我们能够分析有序到无序（发夹到无规卷曲）的转变。振动标记的分配使我们能够确认特定的核苷构象，并获得发夹结构中碱基堆积和碱基配对的信息。此外，从两个高度稳定的CUUG和UUCG四环含有相同的核苷酸，但在不同的顺序获得的数据的比较允许的基础上的拉曼标记证据的结构特征的整体讨论。
CUUG loop is one of the most frequently occurring tetraloops in bacterial 16S rRNA. This tetraloop has a high thermodynamic stability as proved by previous UV absorption and NMR experiments. Here, we present our results concerning the thermodynamic and structural features of the 10mer 5 ' -r(GCG-CUUG-CGC)-3 ', forming a highly stable CUUG tetraloop hairpin in aqueous solution, by means of several optical techniques (UV and IFT-IR absorption, Raman scattering). UV melting profile of this decamer provides a high melting temperature (60.7 degreesC). A set of Raman spectra recorded at different temperatures allowed us to analyze the order-to-disorder (hairpin-to-random coil) transition. Assignment of vibrational markers led us to confirm the particular nucleoside conformation, and to get information on the base stacking and base pairing in the hairpin structure. Moreover, comparison of the data obtained from two highly stable CUUG and UUCG tetraloops containing the same nucleotides but in a different order permitted an overall discussion of their structural features on the basis of Raman marker evidences.