The role played by the RNAs and tRNAs in translation

RNA 和 tRNA 在翻译中发挥的作用

• 批准号: 8010950
• 负责人: RACHEL GREEN
• 金额: $ 34.1万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2013-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8010950
• 关键词: Affect; Amino Acyl Transfer RNA; Antibiotics; Anticodon; Biochemical; Biogenesis; Catalysis; Codon Nucleotides; Complex; Cryoelectron Microscopy; Elements; Fluorescence; Genetic Code; Goals; Kinetics; Measurement; Measures; Messenger RNA; Methods; Molecular; Movement; Mutate; Mutation; Pathway interactions; Peptides; Peptidyltransferase; Play; Process; Protein Biosynthesis; Quality Control; RNA; Research; Resolution; Ribosomal RNA; Ribosomes; Role; Sense Codon; Signal Transduction; Signal Transduction Pathway; Site; Specific qualifier value; Structure; System; Terminator Codon; Therapeutic; Thermodynamics; Transfer RNA; Translations; Variant; Work; design; interest; molecular mechanics; novel; polypeptide; public health relevance; release factor

DESCRIPTION (provided by applicant): The ribosome is the two-subunit macromolecular machine responsible for the decoding of the messenger RNA into the encoded polypeptide - the translation of the genetic code. In fulfilling this essential cellular role, ribosomes carry out a number of discrete functions including selecting the appropriate aminoacyl tRNAs, catalyzing peptide bond formation (PT), accurately translocating the mRNA:tRNA complex and releasing the completed polypeptide chain. Theoretical considerations of the origin of life predict a central role for the rRNAs in translation. This view has been strengthened by the demonstration of catalysis by RNA, extreme conservation observed among rRNA sequences and finally by atomic resolution structures of the ribosome displaying primarily rRNA in the functionally critical regions. The long-term goal of our work is to understand the molecular mechanics of ribosome function. We are particularly interested in understanding how the rRNA and tRNA components of the translation machinery contribute to the overall process of protein synthesis. The advent of atomic resolution structural information and lower resolution information from cryoEM has substantially changed the focus of our research during the past ten years. While the previous challenge was to identify elements of the ribosome located in functionally critical regions, the goal now is to understand how these structurally identified critical components function. The ribosome provides an excellent, tractable system for dissecting molecular movements and examining how they define biologically fundamental signal transduction pathways. All three specific aims are built around pre-steady state kinetic approaches and the analysis of mutated translation components to dissect ribosome function at the molecular level. We are particularly interested in the molecular details of how the ribosome selects the cognate aminoacyl-tRNA on sense codons and the appropriate release factor on stop codons, and how these mechanisms are related. A major new focus of this proposal is the exploration of the mechanistic features of a novel quality control system on the ribosome that takes place following peptide bond formation. PUBLIC HEALTH RELEVANCE: The ribosome is the target of many natural and synthetic antibiotics that affect distinct steps in the translation cycle. Information obtained from detailed molecular studies proposed here will help in defining the features of current antibiotics which make them effective and will aid in the design of more effective therapeutics.

描述（由申请人提供）：核糖体是两个亚基的大分子机器，负责将信使RNA解码成所编码的多肽——遗传密码的翻译。在履行这一重要的细胞作用时，核糖体执行许多离散的功能，包括选择合适的氨酰基 tRNA、催化肽键形成 (PT)、准确易位 mRNA:tRNA 复合物以及释放完整的多肽链。对生命起源的理论思考预测了 rRNA 在翻译中的核心作用。 RNA 催化作用的证明、rRNA 序列中观察到的极端保守性以及最终在功能关键区域主要显示 rRNA 的核糖体的原子分辨率结构都强化了这一观点。我们工作的长期目标是了解核糖体功能的分子机制。我们特别感兴趣的是了解翻译机器的 rRNA 和 tRNA 成分如何促进蛋白质合成的整个过程。原子分辨率结构信息和冷冻电镜的较低分辨率信息的出现极大地改变了我们过去十年的研究重点。虽然之前的挑战是识别位于功能关键区域的核糖体元素，但现在的目标是了解这些结构上识别的关键组件如何发挥作用。核糖体提供了一个优秀的、易于处理的系统，用于剖析分子运动并检查它们如何定义生物学基本信号转导途径。所有三个具体目标都是围绕前稳态动力学方法和突变翻译成分分析建立的，以在分子水平上剖析核糖体功能。我们特别感兴趣的是核糖体如何选择正义密码子上的同源氨酰基-tRNA 和终止密码子上的适当释放因子，以及这些机制如何相关的分子细节。该提案的一个主要新焦点是探索肽键形成后发生的核糖体新型质量控制系统的机械特征。 公共健康相关性：核糖体是许多天然和合成抗生素的靶标，影响翻译周期中的不同步骤。从此处提出的详细分子研究中获得的信息将有助于确定当前抗生素的特征，从而使其有效，并有助于设计更有效的治疗方法。