作者:Huiyan Sun、Jia Sheng、Abdalla E. A. Hassan、Sibo Jiang、Jianhua Gan、Zhen Huang
DOI:10.1093/nar/gks010
日期:2012.6.1
Specificity of nucleobase pairing provides essential foundation for genetic information storage, replication, transcription and translation in all living organisms. However, the wobble base pairs, where U in RNA (or T in DNA) pairs with G instead of A, might compromise the high specificity of the base pairing. The U/G wobble pairing is ubiquitous in RNA, especially in non-coding RNA. In order to increase U/A pairing specificity, we have hypothesized to discriminate against U/G wobble pair by tailoring the steric and electronic effects at the 2-exo position of uridine and replacing the 2-exo oxygen with a selenium atom. We report here the first synthesis of the 2-Se-U-RNAs as well as the 2-Se-uridine ( Se U) phosphoramidite. Our biophysical and structural studies of the Se U-RNAs indicate that this single atom replacement can indeed create a novel U/A base pair with higher specificity than the natural one. We reveal that the Se U/A pair maintains a structure virtually identical to the native U/A base pair, while discriminating against U/G wobble pair. This oxygen replacement with selenium offers a unique chemical strategy to enhance the base pairing specificity at the atomic level.
核碱基配对的特异性为所有生物的遗传信息存储、复制、转录和翻译提供了重要基础。然而,摇摆碱基配对,即 RNA 中的 U(或 DNA 中的 T)与 G 而不是 A 配对,可能会损害碱基配对的高度特异性。在 RNA 中,尤其是在非编码 RNA 中,U/G 摆动配对无处不在。为了提高 U/A 配对的特异性,我们假设通过调整尿苷的 2-exo 位的立体和电子效应,并用一个硒原子取代 2-exo 氧原子,来区分 U/G 摇摆配对。我们在此报告了 2-Se-U-RNA 以及 2-Se-uridine ( Se U) 磷酰胺的首次合成。我们对 Se U-RNA 的生物物理和结构研究表明,这种单原子置换确实可以产生比天然碱基对具有更高特异性的新型 U/A 碱基对。我们发现,Se U/A碱基对保持了与天然U/A碱基对几乎相同的结构,同时对U/G摆动碱基对具有识别作用。这种用硒替代氧的方法提供了一种独特的化学策略,在原子水平上提高了碱基配对的特异性。