Entropy-Driven One-Step Formation of Phi29 pRNA 3WJ from Three RNA Fragments
Entropy-Driven One-Step Formation of Phi29 pRNA 3WJ from Three RNA Fragments
复制标题
DOI：
10.1021/bi4017022
复制
发表时间：
2014-04-15
期刊：
影响因子：
2.9
通讯作者：
Guo, Peixuan
中科院分区：
文献类型：
--
作者：
Binzel, Daniel W.;Khisamutdinov, Emil F.;Guo, Peixuan
核糖核酸纳米技术的新兴领域需要创造具有功能的核糖核酸纳米颗粒，但受到颗粒不稳定性的限制。结果表明，噬菌体phi29马达PRNA的三向连接具有不同寻常的稳定性，可以由三个片段高效地自组装。人们普遍认为，RNA和DNA的折叠是能量景观依赖的，RNA的折叠是由焓驱动的。在这里，我们研究了3WJ组分的热力学特性，如2‘-氟RNA、DNA和RNA。结果表明，这三个片段或以3WJ复合体形式存在，或以单体形式存在，二聚体的中间体几乎检测不到。看来，这三个片段可以在短时间内高效地导致3WJ复合体的形成。测得RNA的解离常数(表观K-D)为11.4 nM，2‘-F嘧啶类化合物使其解离常数增加到4.5 nM，而DNA取代使其减弱为47.7 nM。3WJ(2‘-F)、3WJ(RNA)和3WJ(DNA)的G(37)度分别为-36、-28和-15千卡/摩尔。研究发现，三组分络合物的形成是由熵控制的，而不是通常在RNA络合物中发现的热焓。
The emerging field of RNA nanotechnology necessitates creation of functional RNA nanoparticles but has been limited by particle instability. It has been shown that the three-way junction of bacteriophage phi29 motor pRNA has unusual stability and can self-assemble from three fragments with high efficiency. It is generally believed that RNA and DNA folding is energy landscape-dependent, and the folding of RNA is driven by enthalpy. Here we examine the thermodynamic characteristics of the 3WJ components as 2'-fluoro RNA, DNA, and RNA. It was seen that the three fragments existed either in 3WJ complex or as monomers, with the intermediate of dimers almost undetectable. It seems that the three fragments can lead to the formation of the 3WJ complex efficiently within a rapid time. A low dissociation constant (apparent K-D) of 11.4 nM was determined for RNA, inclusion of 2'-F pyrimidines strengthened the K-D to 4.5 nM, and substitution of DNA weakened it to 47.7 nM. The Delta G(37)degrees, were -36, -28, and -15 kcal/mol for 3WJ(2'-F), 3WJ(RNA), and 3WJ(DNA), respectively. It is found that the formation of the three-component complex was governed by entropy, instead of enthalpy, as usually found in RNA complexes.