Translation Initiation Factor IF3 Structure and Function

翻译起始因子 IF3 结构和功能

• 批准号: 0079305
• 负责人: Robert Simons
• 金额: $ 26.75万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0079305&HistoricalAwards=false
• 关键词: Translation; Initiation; Factor; IF3; Structure

AbstractMCB-0079305SimonsSIMONSThe ribosome is a complex molecular machine that faithfully translates information stored in the genetic code, into enzymes and other proteins. Understanding ribosome function has been and remains one of the most important challenges in molecular biology. The long-term goal of this project is to understand how the ribosome ensures translational accuracy (proper decoding) at its P-site. The P-site decodes information during translation initiation, and work spanning more that two decades has shown that translation initiation factor three (IF3) plays a crucial role in this event, almost certainly by modulating activities that are intrinsic to the ribosome itself. During the past 5 years, important new insights have emerged, including the three-dimensional structure of IF3 and the ribosome, visualization of the IF3/ribosome complex, and new insights into IF3 structure and function. IF3 is thought to operate at or close to the level of P-site function, most likely altering ribosome conformation and thereby the P-site. This modulation of P-site activity probably manifests itself in several seemingly unrelated IF3 effects. These developments hold great promise for an eventual understanding of P-site function and its modulation by IF3. However, before those important goals can be reasonably tackled, several basic and key aspects of IF3 structure and function must first be resolved. This project involves an integrated genetic and biochemical attack on several major unanswered questions at this level. The effects of key IF3 mutations will be examined with a powerful battery of assays designed to monitor IF3 function at several distinct levels of ribosome function. These efforts are instrumental in testing current models for IF3 modulation of ribosome function. IF3 determinants required for interaction with the ribosome will also be explored, and the IF3 binding determinants within the ribosome itself will be identified, in strategies based on existing experimental evidence. These studies are essential for an eventual understanding of how IF3 structure and function are integrated with that of the ribosome. In particular, this work will form a strong underpinning for studies that will eventually tackle IF3 function directly at the P-site.

核糖体是一种复杂的分子机器，它忠实地将储存在遗传密码中的信息翻译成酶和其他蛋白质。了解核糖体的功能一直是分子生物学中最重要的挑战之一。该项目的长期目标是了解核糖体如何确保其p位点的翻译准确性（正确解码）。p位点在翻译起始过程中解码信息，20多年来的研究表明，翻译起始因子3 （IF3）在这一事件中起着至关重要的作用，几乎可以肯定是通过调节核糖体本身固有的活性。在过去的5年中，出现了重要的新见解，包括IF3和核糖体的三维结构，IF3/核糖体复合物的可视化，以及对IF3结构和功能的新见解。IF3被认为在或接近p位点功能水平上起作用，最有可能改变核糖体构象，从而改变p位点。这种p位点活性的调节可能表现为几种看似无关的IF3效应。这些进展对最终理解p位点功能及其由IF3调节具有很大的希望。然而，在合理解决这些重要目标之前，必须首先解决IF3结构和功能的几个基本和关键方面。这个项目涉及到一个综合的基因和生化攻击在这个水平上的几个主要的未解之谜。关键IF3突变的影响将通过一系列强大的检测来检测，这些检测旨在监测IF3在核糖体功能的几个不同水平上的功能。这些努力有助于测试IF3调节核糖体功能的当前模型。还将探索与核糖体相互作用所需的IF3决定因素，并根据现有的实验证据确定核糖体本身内的IF3结合决定因素。这些研究对于最终理解IF3的结构和功能如何与核糖体的结构和功能相结合至关重要。特别是，这项工作将为最终直接解决p位点IF3功能的研究奠定坚实的基础。