RNA BINDING PROTEINS

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 在所有的生命王国中，RNA在合成过程中和合成后都会被修饰，从而通过碱基堆积和氢键的变化改变RNA的稳定性、高阶结构和活性。这些通常保守的修饰位于关键功能区，是实现最佳RNA功能所必需的。大肠杆菌细胞大约0.8%的编码能力专门用于修饰具有独特或有限多位点特异性的RNA的酶。这项建议的目的是确定两个最丰富的RNA修饰酶家族的选择性和催化基础：5-甲基尿嘧啶(m5U0甲基转移酶(MTase)和伪尿苷合成酶(PS)。我们报道的两个m5U MTase的结构已经提出了一个特定识别的模型，在该模型中，RNA底物被重新折叠到酶上，一个碱基被翻出到活性部位。这项工作建议从动力学和结构方面测试、完善和阐述这一模型。我们到目前为止和拟议的对细菌PS的五个亚类的研究修改了tRNAs的茎环(TruA和TruB)、一个茎环(RluD)和一个rRNA的lehix(RluB和RluF)，正在产生位置特异性和区域特异性的模型，这些模型将作为PS在人类健康中发挥作用的范例。因此，随着我们在人类Pus1和Pus3上的拟议工作，这一领域将进入人类生物学的调控领域，这两种酶通过假性激活核受体的RNA激活物(类固醇受体RNA激活剂，SRA)来调节核受体信号。这些酶的缺陷会导致铁粒母细胞性贫血。我们试图确定人tRNA腺嘌呤MTase的结构，作为潜在的抗HIV药物靶点。它会产生一种基本的修饰来控制HIV RNA的逆转录。质谱学分析将有助于鉴定纯化的蛋白质，并最终鉴定翻译后修饰。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. In all kingdoms of life RNAs are modified both during and after synthesis, thereby altering the stability, higher-order structure, and activity of RNA through changes in base stacking and hydrogen bonding. These generally conserved modifications are located at key functional regions and are required for optimal RNA function. Approximately 0.8% of the coding capacity of the E.coli cell is dedicated to enzymes that modify RNA with unique or limited multisite specificity. The aim of this proposal is to determine the basis for selectivity and catalysis in two of the most abundant families of RNA modifying enzymes: 5-methyl uracil (m5U0 methyltransferases (MTases) and pseudouridine synthases (PS). Our reported structures of two m5U MTases have yelded a model for specific recognition in which the RNA substrate is refolded onto the enzyme and a base is flipped out into the active site. This work proposes to test, refine and elaborate that model in kinetic and structural terms. Our to-date and proposed studies of five sub-classes of bacterial PS that modify stem loops of tRNAs (TruA and TruB), a stem loop (RluD), and a lehix (RluB and RluF) of rRNA is yielding models for site specificity and regional specificity that will serve as paradigms for PS that play roles in human health. The field will thus be advanced into regulation in human biology with our proposed work on human Pus1 and Pus3, two enzymes that regulate nuclear receptor signaling by pseudouridylating an RNA activator of nuclear receptors (steroid receptor RNA activator, SRA). Defects in thse enzymes cause sideroblastic anemia. We seek to determine the structure of a human tRNA adenine MTase as a potential new anti-HIV drug target. It generates an essential modification that controls reverse transcription of HIV RNA. Mass Spectroscopy analysis will facilitate the identification of purified proteins and eventually the identification of post-translational modification.