Ribosomal RNA Catalyzed Protein Synthesis

核糖体 RNA 催化蛋白质合成

• 批准号: 0096772
• 负责人: Scott Strobel
• 金额: $ 6.17万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-03-01 至 2003-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0096772&HistoricalAwards=false
• 关键词: Ribosomal; RNA; Catalyzed; Protein; Synthesis

0096772StrobelThe ribosome is the catalyst of peptide bond formation within all living organisms. The 50S ribosomal subunit of the ribosome contains the peptidyl transferase center where the peptide bonds are formed. The recent high resolution crystal structure of the intact 50S subunit suggests that the peptidyl transferase center is composed exclusively of rRNA. The unusual chemical basicity of a single nucleotide within the active site may allow it to serve as a general acid-base catalyst for peptide bond formation. This implies that the ribosome is an RNA enzyme or ribozyme, though this has yet to be biochemically demonstrated. The specific objective of this project is to demonstrate peptidyl transferase activity by an in vitro transcribed 23S rRNA in the absence of ribosomal proteins. To achieve this objective a new version of the peptidyl transferase reaction that alleviates the artifactual reaction conditions required of the previously used fragment reaction will be utilized. The structure of the 50S subunit will be employed to design truncated 23S rRNA fragments that are likely to fold into an active conformation. These experiments are capable of providing definitive biochemical evidence to establish whether 23S rRNA is the catalyst of protein synthesis and will provide a biochemically amenable system for the analysis of the ribosomal reaction mechanism.

0096772 Strobel核糖体是所有生物体内形成肽键的催化剂。核糖体的50S核糖体亚基含有形成肽键的肽基转移酶中心。 最近的高分辨率晶体结构的完整的50 S亚基表明，肽基转移酶中心是由rRNA的专门。 活性位点内单个核苷酸的不寻常的化学碱性可能使其能够作为肽键形成的一般酸碱催化剂。 这意味着核糖体是一种RNA酶或核酶，尽管这还有待生物化学证明。 本项目的具体目标是在不存在核糖体蛋白的情况下通过体外转录的23S rRNA证明肽基转移酶活性。 为了实现这一目标，将使用新版本的肽基转移酶反应，其简化了先前使用的片段反应所需的人为反应条件。 50S亚基的结构将用于设计截短的23S rRNA片段，其可能折叠成活性构象。 这些实验能够提供明确的生物化学证据，以确定是否23S rRNA是蛋白质合成的催化剂，并将提供一个生物化学的核糖体反应机制的分析系统。