Benzaghou Ines, Bougie Isabelle, Picard-Jean Frédéric, Bisaillon Martin
Département de Biochimie, Faculté de Médecine, Université de Sherbrooke, 3001 12e avenue, Sherbrooke, Québ., Canada J1H 5N4.
FEBS Lett. 2006 Feb 6;580(3):867-77. doi: 10.1016/j.febslet.2006.01.006. Epub 2006 Jan 18.
The West Nile virus (WNV) RNA genome harbors the characteristic methylated cap structure present at the 5' end of eukaryotic mRNAs. In the present study, we report a detailed study of the binding energetics and thermodynamic parameters involved in the interaction between RNA and the WNV RNA triphosphatase, an enzyme involved in the synthesis of the RNA cap structure. Fluorescence spectroscopy assays revealed that the initial interaction between RNA and the enzyme is characterized by a high enthalpy of association and that the minimal RNA binding site of NS3 is 13 nucleotides. In order to provide insight into the relationship between the enzyme structure and RNA binding, we also correlated the effect of RNA binding on protein structure using both circular dichroism and denaturation studies as structural indicators. Our data indicate that the protein undergoes structural modifications upon RNA binding, although the interaction does not significantly modify the stability of the protein.
西尼罗河病毒（WNV）的RNA基因组在真核mRNA的5'端具有特征性的甲基化帽结构。在本研究中，我们报告了一项关于RNA与WNV RNA三磷酸酶（一种参与RNA帽结构合成的酶）相互作用中涉及的结合能和热力学参数的详细研究。荧光光谱分析表明，RNA与该酶之间的初始相互作用的特征是具有较高的结合焓，并且NS3的最小RNA结合位点为13个核苷酸。为了深入了解酶结构与RNA结合之间的关系，我们还使用圆二色性和变性研究作为结构指标，将RNA结合对蛋白质结构的影响进行了关联。我们的数据表明，蛋白质在RNA结合时会发生结构修饰，尽管这种相互作用不会显著改变蛋白质的稳定性。
