CRYSTALLOGRAPHIC STUDIES OF RNA-PROTEIN MACHINES

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 正在进行的项目试图通过高分辨率X射线晶体学建立核糖体和相关因子在蛋白质合成中发挥作用的功能机制的结构基础。为了阐明蛋白质合成过程中每个步骤的机制，我们希望获得蛋白质合成周期中尽可能多的步骤中捕获的核糖体晶体，并以尽可能高的分辨率建立它们的结构。其结构将被研究的复合物包括1）70 S核糖体与结合的m-RNA、tRNA和延伸因子的复合物，2）70 S核糖体与含有翻译停滞多肽的P-位点tRNA之间的复合物，和3）70 S核糖体与信号识别颗粒之间的复合物。为了探索细菌核糖体与其来自真核生物的大得多的对应物之间的差异，特别是在蛋白质合成的起始步骤中，将追求40 S亚基、60 S亚基和/或SOS核糖体的结构，包括与IRIS RNA形成的起始复合物，并使用从酵母或兔网织红细胞分离的核糖体。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The projects being pursued try to establish the structural bases for the functional mechanisms by which the ribosome and associated factors achieve their roles in protein synthesis by high resolution X-ray crystallography. To illuminate the mechanisms of each step in the process of protein synthesis, we wish to obtain crystals of the ribosome trapped in as many of the steps in the protein synthesis cycle as possible and to establish their structures at the highest resolution possible. The complexes whose structures will be pursued include those of the 1) 70S ribosome with bound m-RNA, tRNA and elongation factors, 2) complexes between the 70S ribosomal and a P-site tRNA containing a translation arresting polypeptide, and 3) complexes between the 70S ribosome the signal recognition particle. To explore the differences between the bacterial ribosome and its much large counterpart from eukaryotes, particularly in the initiation step of protein synthesis, the structures of the 40S subunit, the 60S subunit and/or the SOS ribosome, including an initiation complex formed with IRIS RNA, and using ribosomes isolated from either yeast or rabbit reticulocyte will be pursued.