NMR STUDIES OF MULV AND SECIS RNA DECODING STIMULATORS

MULV 和 SECIS RNA 解码刺激器的 NMR 研究

• 批准号: 2521167
• 负责人: STEVEN L ALAM
• 金额: $ 3.15万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-06-17 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/2521167
• 关键词: RNA; genetic translation; nuclear magnetic resonance spectroscopy; nucleic acid sequence; nucleic acid structure

Recoding of the genetic code is subject to redirection and redefinition at specific sites in a small number of mRNAs for a wide range of organisms. Redefinition of termination codons can be used to produce larger functional proteins, or alternatively, to insert specialized amino acids (i.e. selenocysteine) into specific points of a protein for altered physical properties. Recoding is under control of information embedded within the mRNA, which is available as specific codons and structured regions in the mRNA (stimulators). A structural understanding of these mRNA stimulators will give insight to the overall mechanisms of redefinition events and a general understanding for translational recoding. A structural investigation of two mRNA stimulatory elements is proposed. (1) The stimulatory element required for selenocysteine insertion in eukaryotes is located in the 3'-UTR and is composed of a stem loop structure with an internal loop. The conserved core region and run of adenosines in the apical loop will be investigated by NMR in terms of structural properties these conserved regions possess. This will clarify discrepancies of two proposed secondary models, and will highlight the importance of loop I in aligning the two helical regions about the core region. (2) The pseudoknot stimulatory element shown to be required for UAG redefinition in Maloney Murine Leukemia Virus (MuLV) will be biophysically probed to tune up the current secondary model produced by genetic approaches, and to interpret highly conserved regions in the proposed loopII and spacer regions. Experiments will be conducted with the presence of a additional element upstream of the UAG termination codon. Competition for the formation of the pseudoknot will be monitored, as well as the efficiency of redefinition. Cellular components that interact with either/both of these elements will be sought through the life cycle of this retrovirus. This information will enable us to produce small model oligonucleotides for high-resolution studies of this pseudoknot stimulator.

遗传密码的重新编码需要重新定向和重新定义 在特定的位点，在一个小数目的mRNA的广泛的 有机体 终止密码子的重新定义可用于产生 更大的功能蛋白质，或者，插入专门的 氨基酸（即硒代半胱氨酸）进入蛋白质的特定位点， 改变了物理性质。信息控制下的数据处理 嵌入在mRNA中，其可作为特定密码子获得， mRNA中的结构化区域（刺激物）。 结构 对这些mRNA刺激因子的了解将使我们了解 重新定义事件的机制和对 翻译重编码 两种mRNA的结构研究 提出了刺激因素。 (1)所需的刺激因素 在真核生物中，硒代半胱氨酸的插入位于3 '-UTR， 由具有内环的茎环结构组成。 的 保守的核心区和腺苷在顶环中的运行将 通过NMR研究这些保守的结构性质， 地区拥有。 这将澄清两个建议的差异 二级模型，并将突出循环I的重要性， 使所述两个螺旋区域围绕所述芯区域对准。 (2)的 假结刺激元件显示为UAG重新定义所需 在马洛尼鼠白血病病毒（MuLV）将进行生物药理学探测， 调整目前由遗传方法产生的二级模型， 为了解释所提出的环II和间隔区中的高度保守区域， 地区 实验将在以下情况下进行： UAG终止密码子上游的额外元件。 竞争 对于伪结的形成将被监测，以及 重新定义的效率。 细胞成分与 这两个要素中的任何一个/两个都将通过生命周期来寻求， 这种逆转录病毒。 这些信息将使我们能够生产小型模型 用于高分辨率研究这种假结的寡核苷酸 刺激器