Cryo-EM analysis of ribosomal frameshifting

核糖体移码的冷冻电镜分析

• 批准号: BB/D013305/1
• 负责人: Robert Gilbert
• 金额: $ 24.84万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FD013305%2F1
• 关键词: Cryo; EM; analysis; ribosomal; frameshifting

Cell proteins are encoded in DNA, the cell's genetic material, and expressed from so-called messenger RNA copied from DNA. This process of expression involves reading a triplet nucleotide code and translating it into an amino acid polymer, the protein. The process of translation involves structures called ribosomes. These move along the messenger RNA decoding the triplets and adding one amino acid for each triplet to the growing amino acid chain. Viruses that infect cells carry their own genetic material and occasionally, they make messenger RNAs that contain a specific signal (called a frameshift signal) that tells the ribosome to stop making one type of triplet and to start making another. The result is that one messenger RNA can make two proteins. This is typical of viruses; as their own genetic material is usually relatively small, they use all sorts of tricks to maximise the number of proteins they can make. In this project, we wish to examine what happens to the ribosome when it encounters a frameshift signal. The question is 'what happens to the ribosome that makes it misbehave?' To answer this, we will purify ribosomes caught in the act of translating through the frameshift signal and study them by microscopy. The microscopy technique we will use is based on electrons rather than light, so is extremely powerful, and is called cryo-electron microscopy. It is 'cryo' because the samples are frozen in aqueous solution before examination to keep them in a natural and stable state. The images we obtain will hopefully tell us something about how the frameshift signal interferes with the ribosome, and should also be informative about how ribosomes work during normal protein synthesis.

细胞蛋白由细胞遗传物质 DNA 编码，并由从 DNA 复制的所谓信使 RNA 表达。这个表达过程涉及读取三联体核苷酸代码并将其翻译成氨基酸聚合物，即蛋白质。翻译过程涉及称为核糖体的结构。它们沿着信使 RNA 移动，解码三联体，并为每个三联体添加一个氨基酸到不断增长的氨基酸链中。感染细胞的病毒携带自己的遗传物质，有时它们会产生含有特定信号（称为移码信号）的信使 RNA，告诉核糖体停止制造一种类型的三联体并开始制造另一种类型。结果是一种信使 RNA 可以产生两种蛋白质。这是病毒的典型特征；由于它们自己的遗传物质通常相对较小，因此它们使用各种技巧来最大限度地增加它们可以制造的蛋白质的数量。在这个项目中，我们希望检查核糖体遇到移码信号时会发生什么。问题是“核糖体发生了什么变化导致其行为异常？”为了回答这个问题，我们将纯化通过移码信号进行翻译的核糖体，并通过显微镜对其进行研究。我们将使用的显微镜​​技术基于电子而不是光，因此非常强大，被称为冷冻电子显微镜。之所以称为“冷冻”，是因为样品在检查前被冷冻在水溶液中，以保持自然稳定的状态。我们获得的图像有望告诉我们移码信号如何干扰核糖体的一些信息，并且还应该提供有关核糖体在正常蛋白质合成过程中如何工作的信息。

项目成果

Viral RNA pseudoknots: versatile motifs in gene expression and replication.

病毒 RNA 假结：基因表达和复制中的多功​​能基序。

• DOI: http://dx.10.1038/nrmicro1704
• 发表时间: 2007
• 期刊: Nature reviews. Microbiology
• 作者: Brierley I

The mechanics of translocation: a molecular "spring-and-ratchet" system.

易位机制：分子“弹簧和棘轮”系统。

• DOI: http://dx.10.1016/j.str.2008.04.001
• 发表时间: 2008
• 期刊: 1993)
• 作者: Moran SJ

A mechanical explanation of RNA pseudoknot function in programmed ribosomal frameshifting.

对程序化核糖体移码中 RNA 假结功能的机械解释。

• DOI: http://dx.10.1038/nature04735
• 发表时间: 2006
• 期刊: Nature
• 影响因子: 64.8
• 作者: Namy O

Ribosomal acrobatics in post-transcriptional control.

转录后控制中的核糖体杂技。

• DOI: http://dx.10.1042/bst0360677
• 发表时间: 2008
• 期刊: Biochemical Society transactions
• 影响因子: 3.9
• 作者: Gilbert RJ