Program in Macromolecular Structure, Motion, Control

信使RNA诱导的蛋白质合成在所有细胞中都是由高度保守的 核糖核蛋白酶称为核糖体。核糖体的原子分辨晶体结构，第一 对我们理解蛋白质合成产生了革命性的影响， 但仍有许多有趣的问题可以最好地用结晶学来解决。这项研究 为未来5年提出的建议有两个组成部分。首先，我们打算用结晶学和遗传学 这里已经为Haloarcula marismortui(HMA)开发了工具，以获得对核糖体的新见解 结构和功能。第二，核糖体和核糖体亚基的晶体将由新的 物种，以便能够回答无法解决的关于核糖体结构和功能的问题 使用任何现在可用的核糖体晶体。 具体地说，假设众所周知的肽基转移酶性质的差异 不同物种核糖体的中心是由其核糖体的核苷酸之间的相互作用引起的。 将在HMA大核糖体中测试具有更远的、非保守核苷酸的保守核心 使用遗传学和结晶学相结合的亚基。同样的工具也将用于确定 肽基转移酶中心如何对高度保守的碱基突变作出构象反应 肽基转移酶中心。此外，还将进行一系列实验，目的是 是制备出口通道中含有新生多肽的大亚基，并解决它们的结构 结晶学上的。最终的目标是制备真核核糖体的晶体，这种晶体的衍射率 原子分辨率，以及它们的结构测定。

Messenger RNA-directed protein synthesis is catalyzed in all cells by a highly conserved ribonucleoprotein enzyme called the ribosome. Atomic resolution crystal structures of ribosomes, the first of which were reported 4 years ago, have had a revolutionary impact on our understanding of protein synthesis, but many interesting questions remain that can best be approached crystallographically. The research proposed for the next 5 years has two components. First, we intend to use the crystallographic and genetic tools already developed here for Haloarcula marismortui (Hma) to obtain new insights into ribosome structure and function. Second, crystals of ribosomes and ribosomal subunits will be prepared from new species so that questions about ribosome structure and function can be answered that cannot be addressed using any of the ribosome crystals now available. Specifically, the hypothesis that the well known differences in the properties of the peptidyl transferase centers of the ribosomes from different species are caused by interactions between the nucleotides in its conserved core with more remote, non-conserved nucleotides will be tested in the Hma large ribosomal subunit using a combination of genetics and crystallography. The same tools will also be used to determine how the peptidyl transferase center responds conformationally to the mutation of highly conserved bases in the peptidyl transferase center. In addition, a series of experiments will be carried out the objective of which is to prepare large subunit that have nascent peptides in their exit tunnels, and solve their structures crystallographically. The final goal is the preparation of crystals of eukaryotic ribosomes that diffract to atomic resolution, and the determination of their structures.