Does the ribosomal E site help hold the reading frame?

核糖体 E 位点是否有助于保持阅读框？

• 批准号: 7072011
• 负责人: James F. CURRAN
• 金额: $ 20.92万
• 依托单位: WAKE FOREST UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7072011
• 关键词: RNA binding protein; SDS polyacrylamide gel electrophoresis; acylation; aminoacyl tRNA; binding sites; frameshift mutation; genetic translation; open reading frames; protein biosynthesis; ribosomal proteins; ribosomes; transfection

DESCRIPTION (provided by applicant): Maintenance of the translational reading frame is a fundamentally important feature of protein synthesis. There is clear evidence that ribosomes contain an "exit" or "E" site for deacylated tRNA, and that tRNA pass through the E site after completing their translational role. But except for transient interactions with the exiting tRNA, no other clear function has been identified for the E site. However, recent evidence leads to the hypothesis that deacylated tRNA in the ribosomal E site helps prevent frameshifting. We propose four experimental tests of this hypothesis. We will determine whether the E site is holds tRNA until an aminoacyl- tRNA is selected at the A site. If so, then the E site tRNA might have an important functional role in translation of the A site. If not, then the E site is probably just an exit path. We will also determine whether message nucleotides and tRNA sequences in the E site are associated with increased or decreased frameshifting at the RF2 programmed frameshift site. Preliminary work shows that the E site triplet is important, although the mechanisms are not yet clear. Proposed work will define its role. Finally, we will determine whether an E site tRNA establish the reading frame on ribosomes in vitro.

描述（由申请人提供）：翻译阅读框的维持是蛋白质合成的一个基本重要特征。有明确的证据表明核糖体含有脱酰化 tRNA 的“退出”或“E”位点，并且 tRNA 在完成其翻译作用后会穿过 E 位点。但除了与现有 tRNA 的短暂相互作用外，E 位点尚未发现其他明确的功能。然而，最近的证据得出这样的假设：核糖体 E 位点的脱酰 tRNA 有助于防止移码。我们提出了这个假设的四个实验检验。我们将确定 E 位点是否保留 tRNA，直到在 A 位点选择氨酰基 tRNA。如果是这样，那么 E 位点 tRNA 可能在 A 位点的翻译中具有重要的功能作用。如果没有，那么E站很可能只是一个退出路径。我们还将确定 E 位点中的信息核苷酸和 tRNA 序列是否与 RF2 编程移码位点的移码增加或减少相关。初步研究表明，E 位点三联体很重要，但其机制尚不清楚。拟议的工作将定义其作用。最后，我们将确定 E 位点 tRNA 是否在体外建立核糖体上的阅读框。