Stabilization of RNA stacking by pseudouridine
Stabilization of RNA stacking by pseudouridine
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DOI：
10.1093/nar/23.24.5020
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发表时间：
1995-12-25
影响因子：
14.9
通讯作者：
Davis, DR
中科院分区：
文献类型：
--
作者：
Davis, DR
将修饰的核苷假氨酸（PSI）与尿苷进行比较。通过H-1 NMR，UV和CD光谱法测量了模型RNA寡核苷酸中的碱基堆叠程度，UV和CD的结果表明，模型的单链寡核苷酸AAAUA和AA psi模型在溶液中堆叠了溶液中的结构和CD结果。对于AA PSI A与一般A形式的螺旋构象一致，AA PSI A低聚物展示在温度范围5-55度C上，更高程度的紫外线低色素性与与AAUA相比，与更好堆叠的A形式结构一致，每种核苷酸残基的堆叠程度是从3'- Endo糖配方中推断出来的如H1'-H2'NMR标量耦合所示，这种间接堆叠的指示通过顺序NOE连接模式证实NMR测量值是从2D Roesy NMR实验中获得的，随着温度的函数表明，假氨酸比尿疗形成了更稳定的基础堆叠布置，这种效果在整个螺旋中均能稳定相邻的嘌呤核苷。 AA PSI A中的N1-H Imino质子与溶剂缓慢交换，这表明额外的伊米诺质子质子在稳定假氨酸构象中的作用。这些结果表明，构象稳定是出现在核苷酸水平上的假氨酸的固有特性，这些模型中假氨酸的特征与早期对完整tRNA的研究一致，表明假氨酸在大多数结构环境中可能在相同的稳定范围内发挥了相同的稳定功能。
The effect of the modified nucleoside pseudouridine (Psi) on RNA structure was compared with uridine. The extent of base stacking in model RNA oligonucleotides was measured by H-1 NMR, UV, and CD spectroscopy, The UV and CD results indicate that the model single-stranded oligoribonucleotides AAUA and AA Psi A form stacked structures in solution and the CD results for AA Psi A are consistent with a general A-form helical conformation, The AA Psi A oligomer exhibits a greater degree of UV hypochromicity over the temperature range 5-55 degrees C, consistent with a better stacked, more A-form structure compared with AAUA, The extent of stacking for each nucleotide residue was inferred from the percent 3'-endo sugar conformation as indicated by the H1'-H2' NMR scalar coupling, This indirect indication of stacking was confirmed by sequential NOE connectivity patterns obtained from 2D ROESY NMR experiments, NMR measurements as a function of temperature indicate that pseudouridine forms a more stable base stacking arrangement than uridine, an effect that is propagated throughout the helix to stabilize stacking of neighboring purine nucleosides. The N1-H imino proton in AA Psi A exchanges slowly with solvent, suggesting a role for the extra imino proton in stabilizing the conformation of pseudouridine. These results show that the conformational stabilization is an intrinsic property of pseudouridine occurring at the nucleotide level, The characteristics of pseudouridine in these models are consistent with earlier studies on intact tRNA, indicating that pseudouridine probably performs the same stabilizing function in most structural contexts.