5S rRNA: topology and function

描述(由申请人提供) 核糖体是极其精确的细胞蛋白质的中心成分。 合成仪器。它的工作是通过以下方式快速而准确地解码mRNA 阅读三个碱基的“密码子”随着分子遗传学的出现，它已经成为 有可能创造和检测个体核糖体突变的影响 不同核糖体相关功能组分的专门化分析 系统。这些新工具在经典生化方法中的应用有 从而加深了对许多核糖体的作用的理解 蛋白质和核糖体RNA(RRNAs)在决定核糖体如何维持中发挥作用 翻译阅读框架。现在很明显，rRNAs是中枢 在核糖体催化的反应中扮演着重要角色，单个rRNA 都积极参与不同的核糖体功能。然而，尽管它是 在整个进化过程中高度保守，无处不在的 5S rRNA仍未确定。过去，5S研究的主要障碍是 Rrna是一个事实，即真核细胞含有多个染色体拷贝的 5S rDNA基因，它排除了对5S rRNA功能的任何遗传解剖， 或核糖体背景下的结构研究。我们已经克服了这一点 通过构建一株表达所有5S rRNA的菌株来设置障碍 携带质粒的克隆。应用该系统进行5S rRNA的整体诱变研究 揭示了表明5S rRNA新功能的新表型，我们 现在准备将5S rRNA的功能方面与其内部结构联系起来 核糖体。为此，我们得到了Olga A.Dontsova博士的帮助， 他是世界一流rRNA结构实验室的负责人。建议数 合作将利用Dinman的遗传和生化优势 拥有Dontsova博士公认的分子和生化专业知识的实验室 S组。这项提案的主要目的是确定 5S rRNA自身拓扑上的突变，以及另一种拓扑上的结构突变 主要的rRNA。该项目的设计是为了从这些影响中建立起 突变体通过其对5S rRNA的影响而单独影响其结构 与核糖体蛋白L5结合，进而对完整核糖体的研究 60S亚基和整个核糖体。这项研究将主要在 俄罗斯作为美国国立卫生研究院#R01-GM62143号赠款的延伸。从以下方面收集的信息 这些研究将极大地扩展我们对 真核rRNA的结构相互作用，并将提供科学的 社区对5S rRNA如何帮助确保 核糖体将生物体的遗传信息准确地翻译成 蛋白质。

DESCRIPTION (provided by applicant) The ribosome is the central component of an extremely accurate cellular protein synthetic apparatus. Its job is to rapidly and accurately decode mRNAs by reading three base "codons." With the advent of molecular genetics, it has been possible to create and examine the effects of mutants of individual ribosomal components on different ribosome-associated functions using specialized assay systems. The application of these new tools to classic biochemical methods are leading to a deeper understanding of the roles that many of the ribosomal proteins and ribosomal RNAs (rRNAs) play in determining how ribosomes maintain translational reading frame. It is now clear that the rRNAs are the central players in the reactions catalyzed by ribosomes, and that the individual rRNAs are actively involved in different ribosome functions. However, although it is highly conserved throughout evolution, the precise function of the ubiquitous 5S rRNA remains undetermined. In the past, the major barrier to studies of 5S rRNA was the fact that eukaryotic cells harbor multiple chromosomal copies of the 5S rDNA genes, which precluded any genetic dissection of 5S rRNA function, or structural studies within the context of the ribosome. We have overcome this hurdle by constructing a strain in which all 5S rRNAs are expressed from plasmid-borne clones. A global mutagenesis study of 5S rRNA using this system has revealed novel phenotypes indicative of new functions for 5S rRNA, and we are now poised to link functional aspects of 5S rRNA to its structure within the ribosome. To this end, we have enlisted the aid of Dr. Olga A. Dontsova, chief of one of the world's premier rRNA structural laboratories. The proposed collaboration will exploit the genetic and biochemical strengths of the Dinman laboratory with the proven molecular and biochemical expertise of Dr. Dontsova' s group. The broad aim of this proposal is to determine the effects of mutations in 5S rRNA on its own topology, and on the structures of the other major rRNAs. The project is designed to build up, from the effects of these mutants on the structure of 5S rRNA alone, through their effects on its association with ribosomal protein L5, and then to studies on intact ribosomal 60S subunits and whole ribosomes. This research will be done primarily in Russia as an extension of NIH grant # R01-GM62143. The information gleaned from these studies will represent a tremendous expansion of our knowledge of eukaryotic rRNA structural interactions, and will provide the scientific community with an entirely new understanding of how 5S rRNA helps to ensure that ribosomes accurately translate an organisms' genetic information into proteins.