Remarkable morphological variability of a common RNA folding motif: The GNRA tetraloop-receptor interaction
Remarkable morphological variability of a common RNA folding motif: The GNRA tetraloop-receptor interaction
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DOI：
10.1006/jmbi.1996.0810
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发表时间：
1997-02-28
影响因子：
5.6
通讯作者：
Pyle, AM
中科院分区：
文献类型：
--
作者：
Abramovitz, DL;Pyle, AM
最常见的RNA三级相互作用之一涉及GNRA发夹环与RNA其他区域的茎环结构的对接。第二组内含子的结构域5通过这样的相互作用与结构域1相互作用，已经对ai5g内含子的热力学和动力学进行了表征。使用这个系统，有可能测试参与三级相互作用的GNRA四元环的形态容差。这里提供的数据表明，GNRA四环在环内的任何磷酸二酯键被物理切割后仍然可以参与三级相互作用。‘’四环‘’可以被许多核苷酸在两个方向上扩展，并且共价连续的环也可以在不损失相互作用能量的情况下扩展。在镍四环的背景下，四环序列的第二核苷酸可以完全缺失而不会失去功能。通过研究四环结构中的自由基变化，本研究有助于定义参与远程三级相互作用的GNRA基序的最小序列和结构要求。研究表明，能够形成三级相互作用的“四环”式结构可以嵌入到意想不到的环境中，例如RNA中的内部环和明显的开放结构。它证明了五角龙和六角鸟可以形成与四角鸟相同类型的相互作用，具有几乎相同的亲和力。综上所述，这些数据为GNRA四环-受体相互作用提出了一个更一般的术语：这里建议将术语‘’GNRA四环‘’替换为‘’GN(N)/RA‘’，其中n表示可变数量的核苷酸和/或指示环可以被其他序列分割和中断。(C)1997年学术出版社有限公司。
One of the most common RNA tertiary interactions involves the docking of GNRA hairpin loops into stem-loop structures on other regions of RNA. Domain 5 of the group II intron interacts with Domain 1 through such an interaction, which has been characterized thermodynamically and kinetically for the ai5g intron. Using this system, it was possible to test the morphological tolerances of the GNRA tetraloop involved in tertiary interactions. The data presented herein show that a GNRA tetraloop can still participate in tertiary interaction after being physically cut at any phosphodiester linkage within the loop. The ''nicked tetraloop'' can be expanded by many nucleotides in either direction and the covalently continuous loop can also be expanded without loss of interaction energy. In the context of the nicked tetraloop, the second nucleotide of the tetraloop sequence can be completely deleted without loss of function. By examining radical alterations in tetraloop structure, this study helps define the minimal sequence and structural requirements of a GNRA motif involved in long-range tertiary interaction. It shows that ''tetraloop''-like structures capable of forming tertiary interactions can be imbedded in unexpected contexts, such as internal loops and apparently open structure within RNA. It demonstrates that pentaloops and hexaloops can form the same type of interaction, with almost equal affinity, as a tetraloop. Taken together, these data suggest a more generic term for the GNRA tetraloop-receptor interaction: It is proposed herein that the term ''GNRA tetraloop'' be replaced by ''GN(n)/RA'', where n represents a variable number of nucleotides and / indicates that the loop can be divided and interrupted by other sequences. (C) 1997 Academic Press Limited.