A Study of Site-Specifically Modified RNAs

超出所提供的空间。 建议继续研究位点特异性修饰的RNA，其中将采取合成和生物物理方法的组合。这项工作的长期目标是了解修饰的核苷在RNA中的功能意义及其在调节RNA相互作用中的作用。新的RNA靶向药物或基于RNA的治疗方法的设计最终将依赖于对RNA结构-功能关系的基本理解。短期目标是获得有关天然修饰碱基（如假尿苷）的作用及其对RNA结构和稳定性的贡献的详细信息。将被合成和结构表征的修饰RNA是E. coli 23 S rRNA和真核生物中类似的大亚基rRNA发夹结构。这些RNA含有高度保守的假尿苷修饰和已显示在核糖体组装中起作用的核苷酸序列。 将拟定结构研究的结果与rive功能研究的结果进行比较。本研究计划的具体目标如下：1）研究大肠杆菌螺旋69（1906-1924残基）上修饰的19-nt RNA发夹的生物物理性质和三维结构。coli 23 S rRNA的结构和性质。2）1920-区RNA的完全修饰的19-nt人类似物的结构和性质。3）通过与过渡金属络合物和有机试剂的反应，比较19-nt、完全修饰的1920-区域RNA构建体和全长、生物学相关的大亚基rRNA的结构，和4）鉴定对细菌1920-区域RNA结构具有特异性的配体，并用于研究1920 RNA功能。总之，所提出的实验将用于确定是否修饰的碱基，如假尿苷或3-甲基假尿苷影响局部RNA结构足以提供合适的识别元件，用于选择性药物靶向。性能现场=

EXCEED THE SPACE PROVIDED. A continued study of site-specifically modified RNAs is proposed in which a combination of syn- thetic and biophysical approaches will be taken. The long-term goal of the work is to understand the functional significance of modified nucleosides in RNA and their roles in regulation of RNA inter- actions. The design of new RNA-targeting drugs or RNA-based therapeutics will ultimately rely on a fundamental understanding of RNA structure-function relationships. The short term goal is to ob- tain detailed information regarding the roles of natural modified bases such as pseudouridine and their contributions to RNA structure and stability. Modified RNAs that will be synthesized and struc- turally characterized are an exposed hairpin in domain IV of E. coli 23S rRNA and the analogous large subunit rRNA hairpin in eukaryotes. These RNAs contain highly conserved pseudouridine modifications and nucleotide sequences that have been shown to play a role in ribosome assembly. Results of the proposed structure studies will be compared to in rive functional studies. The specific aims of the research plan are as follows: 1) the biophysical properties and three-dimensional struc- tures of modified 19-nt RNA hairpins from helix 69 (residues 1906-1924) ofE. coli 23S rRNA will be determined 2) the structure and properties of a fully modified 19-nt human analogue of the 1920- region RNA from E. coli will be determined, 3) the structures of the 19-nt, fully modified 1920- region RNA constructs and full-length, biologically relevant, large subunit rRNAs will be compared by reactions with transition metal complexes and organic reagents, and 4) ligands that have specific- ity for the bacterial 1920-region RNA structure will be identified and used to study the 1920 RNA function. Taken together, the proposed experiments will be used to determine whether modified bases such as pseudouridine or 3-methylpseudouridine influence local RNA structure enough to provide suitable recognition elements for selective drug targeting. PERFORMANCE SITE ========================================Section End===========================================