STRUCTURAL CHARACTERIZATION OF THE INTERACTION BTW DIANTHOVIRUS RNA-1 AND RNA-2

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 病毒使用一套不同的机制来转录调节蛋白质的表达。最新的转录调控机制之一是在双花病毒的单链、两部分RNA基因组中发现的。RNA-2编码区的20个核苷酸与外壳蛋白亚基因组mRNA启动子RNA-1的8个核苷酸之间的RNA-RNA相互作用已被证明(1)。为了进一步用核磁共振波谱方法表征这一机理，我们制备了一个短的合成寡核苷酸的模型体系。通过热变性和核磁共振方法测定，RNA-2的20聚类似物形成了发夹状环结构，其中稳定的G：U碱基关闭了环：1.合成的双分子RNA-2和RNA-1复合物的动力学使其不适合于高分辨率三维结构的测定。双花叶病毒序列保守和核磁共振结果的组合提供了足以产生低分辨率模型的结构限制3。该模型的总体特征是两个螺旋区域，RNA-2发夹的茎和RNA-2环和RNA-1之间的碱基配对形成的螺旋。该复合体中有七个碱基对。该结构与伪节的结构特征有相似之处。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Viruses use a diverse set of mechanisms for transcriptional regulation of protein expression. One of the most novel transcription regulation mechanisms is found in the single stranded, bipartite RNA genomes of dianthoviruses. An RNA-RNA interaction between an 20 nucleotide element in the coding region of RNA-2 and an 8 nucleotide element of the coat protein subgenomic mRNA promoter RNA-1 has been previously demonstrated (1). To further characterize this mechanism by the NMR spectroscopy method, a model system of short synthetic oligonucleotides was prepared. The 20mer analog of RNA-2 forms a hairpin loop structure with a stable G:U basepair closing the loop as determined by thermal denaturation and NMR methods:1. The dynamics of the synthetic bi-molecular RNA-2 and RNA-1 complex make it unsuited for determination of a high resolution 3 dimensional structure2. The combination of dianthovirus sequence conservation and NMR results provide structural restrains sufficient to generate a low resolution model3. The general features of the model are two helical regions, the stem of the RNA-2 hairpin and a helix formed by the base pairing between the RNA-2 loop and RNA-1. Seven base pairs are present in the complex . The structure has similarity to the structural features of pseudoknots.