Recognition of pre-formed and flexible elements of an RNA stem-loop by nucleolin
Recognition of pre-formed and flexible elements of an RNA stem-loop by nucleolin
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DOI：
10.1006/jmbi.2001.4691
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发表时间：
2001-06-08
影响因子：
5.6
通讯作者：
Feigon, J
中科院分区：
文献类型：
--
作者：
Bouvet, P;Allain, FHT;Feigon, J
核仁素是一种含量丰富的核仁蛋白，是核糖体生物合成所必需的。其四个串联RNA结合结构域中的前两个（RBD 12）特异性识别茎环结构，该茎环结构在环中含有保守的UCCCGA序列，称为核仁识别元件（NRE）。我们已经确定了结构的共识SELEX NRE（sNRE）的NMR光谱。在游离和结合的RNA中，茎的顶部形成环E（或S-转角）基序。在不存在蛋白质的情况下，由于构象异质性，发夹环的结构没有很好地定义，并且似乎在两个构象家族之间处于平衡状态。用sNRE滴定RBD 1、RBD 2和RBD 12表明特异性结合需要RBD 12。在与RBD 12的复合物中，发夹环与蛋白质特异性相互作用，并采用明确定义的结构，该结构共享游离形式的一些特征。环E基序也与蛋白质具有特异性相互作用。这些研究结果的影响模块化蛋白质的RNA结构的识别机制进行了讨论。(C)北京：科学出版社.
Nucleolin is an abundant nucleolar protein which is essential for ribosome biogenesis. The first two of its four tandem RNA-binding domains (RBD12) specifically recognize a stem-loop structure containing a conserved UCCCGA sequence in the loop called the nucleolin-recognition element (NRE). We have determined the structure of the consensus SELEX NRE (sNRE) by NMR spectroscopy. In both the free and bound RNA the top part of the stem forms a loop E (or S-turn) motif. In the absence of protein, the structure of the hairpin loop is not well defined due to conformational heterogeneity, and appears to be in equilibrium between two families of conformations. Titrations of RBD1, RBD2, and RBD12 with the sNRE show that specific binding requires RBD12. Ln complex with RBD12 the hairpin loop interacts specifically with the protein and adopts a well-defined structure which shares some of the features of the free form. The loop E motif also has specific interactions with the protein. Implications of these findings for the mechanism of recognition of RNA structures by modular proteins are discussed. (C) 2001 Academic Press.