SOLUTION STUDY BY SAXS OF THE SIGNAL RECOGNITION PARTICLE FROM THERMUS AQUATICUS

水栖动物信号识别粒子的SAXS解研究

• 批准号: 7370448
• 负责人: Pascal Francois Egea
• 金额: $ 0.43万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7370448
• 关键词: SOLUTION; STUDY; SAXS; SIGNAL; RECOGNITION

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The signal recognition particle (SRP) and its membrane-associated receptor (SR) constitute an evolutionary conserved macromolecular ribonucleoproteic complex that catalyzes targeting of nascent secretory and membrane proteins to the protein translocation apparatus. The SRP is in charge of directing ribosomes which are currently translating proteins destined Rr either secretion or membrane integration to the endoplasmic reticulum or plasma membrane. The receptor is responsible for the targeting of the ribosome-nascent protein-SRP complex to the membrane translocation machinery. The components of the SRP pathway and the essential steps of the molecular mechanism of SRP-dependent protein targeting are conserved in all three kingdoms of life. The thermostable signal recognition particle from the eubacteria Thermus aquaticus (Taq) is a ribonucleic acid-protein complex composed of the SRP-RNA, which is 113 nucleotides long (35 kDal), and two proteins, the receptor subunit FtsY (33 kDal) and the RNA and signal sequence-binding subunit Ffli (48 kDal). In addition both proteins are structurally related GTPases and GTP-dependent GTPase-activating proteins (GAPs). The ribosome-nascent protein-SRP complex interaction with its receptor is also GTP dependent. GTP hydrolysis by the SRP-SR complex dissociates this complex, allowing a new round of targeting. All components of the Taq-SRP are overexpressed and soluble and have been extensively characterized by gel filtration, dynamic light scattering and analytical ultracentrifugation, in terms of homogeneity and stability. The aim of this biophysical study by SAXS is to characterize the shapes and the conformations of the Taq-SRP and its subcomponents in solution.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。信号识别颗粒（SRP）及其膜相关受体（SR）构成了进化上保守的大分子核糖核蛋白复合物，催化新生分泌蛋白和膜蛋白靶向蛋白质易位装置。SRP负责指导核糖体，核糖体目前正在翻译蛋白质，这些蛋白质被指定为分泌或膜整合到内质网或质膜。该受体负责将核糖体-新生蛋白-SRP复合物靶向至膜易位机构。SRP途径的组分和SRP依赖性蛋白靶向的分子机制的基本步骤在所有三个生命王国中是保守的。来自真细菌水生栖热菌（Taq）的热稳定信号识别颗粒是由SRP-RNA（其为113个核苷酸长（35 kDal））和两种蛋白质（受体亚基FtsY（33 kDal）和RNA和信号序列结合亚基Ffli（48 kDal））组成的核糖核酸-蛋白质复合物。此外，这两种蛋白质都是结构相关的GTP酶和GTP依赖性GTP酶激活蛋白（GAP）。核糖体-新生蛋白-SRP复合物与其受体的相互作用也是GTP依赖性的。通过SRP-SR复合物的GTP水解使该复合物解离，从而允许新一轮靶向。Taq-SRP的所有组分均过表达且可溶，并已通过凝胶过滤、动态光散射和分析超离心在均匀性和稳定性方面进行了广泛表征。SAXS生物物理研究的目的是表征Taq-SRP及其子组分在溶液中的形状和构象。