Molecular genetics of translational accuracy

核糖体上的蛋白质合成过程是最古老的生物机制之一， 在第一个细胞之前，核糖体可能是在rna世界中进化的，它已经进化出一种精心制作的 结构，保存在生命所有领域的基本部分，理解 核糖体忠实地将mRNAs翻译成蛋白质变得更加重要和容易处理 随着细菌核糖体两个亚单位具有不同的多种分子结构 配基， 我们的实验室多年来一直对信使核糖核酸如何测序的问题感兴趣 与核糖体相互作用导致程序性错误，我们主要研究了 程序化的翻译框架转换，在这种转换中，mRNAs中的特定位点会刺激翻译错误 在比mRNAs中随机位置大几个数量级的速率下，我们和 其他人揭示，程序化的移码位点操纵核糖体的解码中心，以 加剧错误。 最近，我们的研究表明，我们已经开始研究错义错误的机制 误差因误判误差的类型(第一、第二或摆动位置错配)而变化很大 根据参与解码密码子的tRNA等受体，该密码子是错误的位置。少校 我们工作的结论是，摆动误差是常见的，尽管它们不是普遍存在的，而且 当竞争的同源tRNA供应不足时，会发生其他类型的错误 通过错误的tRNA解码，我们建议进一步刻画错义错误的现象 通过创建一组基于E、Coli LacZ和Photinus(萤火虫)荧光素酶的错误报告结构 基因。 Venki Ramakrishnan提出，精度机制的主要部分要求 破坏核糖体蛋白S4(RPS4)和rpS5之间的蛋白质相互作用，从而允许 核糖体转变为封闭的构象，捕获A位点的氨基酰-tRNA，并允许 EF-L A.GDP的退出，该模型是基于以界面为目标的突变体的存在 被提议破坏它的稳定并导致错误增加，我们的初步数据与此不一致 假设，我们建议通过识别改变准确性的新突变来进一步检验该假设， 无论是在rRNA还是核糖体蛋白中， 核糖体上的蛋白质合成过程是 在最古老的生物机制中， 可能是在RNA世界中进化的，在 首先是细胞，核糖体进化出了一种复杂的 结构，所有领域都保存的基本部分 对生命的理解，理解生命 核糖体忠实地将mRNAs翻译成蛋白质 变得更加重要，也变得更加容易处理 随着多种分子结构的出现 细菌核糖体的两个亚基具有不同的 配基， 我们实验室多年来一直对 关于信使核糖核酸序列的问题 与核糖体相互作用导致程序化 错误，我们主要研究了错误的机制 程序化平移框架，其中 MRNAs中的特定位点刺激翻译 错误 以比以大几个数量级的速度 MRNAs中的随机位置、我们的工作和 其他人透露，程序化的框架转换网站 操纵核糖体的解码中心来 加剧错误。 最近，我们开始研究 我们的研究表明，误判错误的机制 误差因误判误差的类型而变化很大 (第一、第二或摆动位置错配)和 根据参与其中的tRNA等位受体 解码错误所在位置的密码子。这个 我们工作的结论是摆动误差 通常发生，尽管它们不是普遍存在的，而且 那 其他类型的错误发生在竞争时

The process of protein synthesis on the ribosome is among the oldest of biological mechanisms, having evolved probably in the RNA world before the first cells, The ribosome has evolved an elaborate structure, the essential parts conserved in all domains of life, Understanding the mechanism by which the ribosome faithfully translates mRNAs into proteins has become both more important and more tractable with the availability of multiple molecular structures of both subunits of bacterial ribosomes with various ligands, Our laboratory for many years has been interested in the problem of how mRNA sequences interact with the ribosome to cause programmed errors, We have mainly studied the mechanism of programmed translational frameshifting in which particular sites in mRNAs stimulate translational errors at rates several orders of magnitude greater than at random positions in mRNAs, Our work and that of others revealed that programmed frameshift sites manipulate the decoding center of the ribosome to exacerbate errors. More recently, we have begun to study the mechanism of missense errors, Our study has shown that errors vary widely by type of missense error (first, second or wobble position mispairing) and according to the tRNA isoacceptors involved in decoding the codon that is the site of the error. The major conclusion of our work is that wobble errors commonly occur, tllOugh they are not universal, and that other types of errors occur when the competing cognate tRNA is in insufficient supply to preclude decoding by the errant tRNA, We propose to further characterize the phenomenology of missense errors by creating a set of error-reporter constructs based on the E, coli lacZ and the Photinus (firefly) luciferase genes. Venki Ramakrishnan has proposed that a major part of the accuracy mechanism requiring the disruption ofa protein.protein interaction between ribosomal proteins S4 (rpS4) and rpS5, which allows the ribosome to shift into a "closed" conformation that traps the aminoacyl-tRNA in the A site and allows exit of EF-l A.GDP, The model is based on the existence of mutants targeting the interface that are proposed to destabilize it and cause increased errors, Our preliminary data are inconsistent with this hypothesis, We propose to further test the hypothesis by identifying novel mutations that alter accuracy, either in the rRNA or ribosomal proteins, The process of protein synthesis on the ribosome is among the oldest of biological mechanisms, having evolved probably in the RNA world before the first cells, The ribosome has evolved an elaborate structure, the essential parts conserved in all domains of life, Understanding the mechanism by which the ribosome faithfully translates mRNAs into proteins has become both more important and more tractable with the availability of multiple molecular structures of both subunits of bacterial ribosomes with various ligands, Our laboratory for many years has been interested in the problem of how mRNA sequences interact with the ribosome to cause programmed errors, We have mainly studied the mechanism of programmed translational frameshifting in which particular sites in mRNAs stimulate translational errors at rates several orders of magnitude greater than at random positions in mRNAs, Our work and that of others revealed that programmed frameshift sites manipulate the decoding center of the ribosome to exacerbate errors. More recently, we have begun to study the mechanism of missense errors, Our study has shown that errors vary widely by type of missense error (first, second or wobble position mispairing) and according to the tRNA isoacceptors involved in decoding the codon that is the site of the error. The conclusion of our work is that wobble errors commonly occur, tllOugh they are not universal, and that other types of errors occur when the competing