Structure & Function of Bacteriophage Portal Proteins

结构

• 批准号: 1051715
• 负责人: Peter Prevelige
• 金额: $ 60.35万
• 依托单位: University of Alabama at Birmingham
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-02-01 至 2015-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1051715&HistoricalAwards=false
• 关键词: Structure; & Function; Bacteriophage; Portal

Intellectual MeritThe project focuses on deciphering the sequence of protein/protein interactions which occur during the assembly of viral capsids using the bacteriophage phi29 as a model system. Viral capsids are protective protein shells that self assemble from hundreds of chemically identical protein molecules. In the final capsid these molecules are precisely positioned in space with an overall spherical form. The protein shell surrounds and protects the viral nucleic acid and in one class of capsid the shell assembles first and the nucleic acid is subsequently pumped into the shell through a conduit known as a portal. Despite the ubiquity of this architectural theme, little is known about the pathway or sequence of protein/protein interaction through which the proteins self-assemble. Recent experimental data suggests that assembly nucleates from a complex composed of multiple copies of two proteins, a scaffolding protein and the conduit forming portal protein. The project will use chemical cross-linking/mass spectrometry, hydrogen/deuterium exchange studies and mutational analysis in concert with computational docking to determine the detailed structure of this nucleation complex, and use this information to chemically stabilize the nucleation complex. The stabilized nucleation complexes will then be used to seed assembly reactions both in bulk solution and in single molecule experiments to probe the sequence and kinetics of subunit addition to growing capsids and derive a molecular level understanding of the assembly pathway.Broader ImpactA detailed quantitative description of the molecular pathway of viral capsid assembly is required by the cadre of physicist and mathematicians who are developing models of self-assembly using viruses as a paradigm and a description at this level of detail is not currently available for any virus. The research project itself employs a wide variety of biophysical and biochemical tools and serves as an ideal training platform for the graduate and undergraduate students who will be carrying out the experiments. Finally, because detailed molecular pathways are best appreciated and understood when illustrated by animation the assembly pathway defined by this project will be animated for a lay audience by students in the Department of Art and the Art History Department exposing them to frontline science while allowing them to refine their animation skills and develop a portfolio.

智力优点该项目的重点是破译蛋白质/蛋白质相互作用的序列，在使用噬菌体phi 29作为模型系统的病毒衣壳组装过程中发生。病毒衣壳是一种保护性的蛋白质外壳，由数百个化学性质相同的蛋白质分子自行组装而成。在最终的衣壳中，这些分子以整体球形形式精确地定位在空间中。蛋白质壳包围并保护病毒核酸，在一类衣壳中，壳首先组装，随后核酸通过称为门户的导管泵入壳中。尽管这种架构主题无处不在，但对蛋白质自组装的蛋白质/蛋白质相互作用的途径或序列知之甚少。最近的实验数据表明，组装成核的复杂组成的两个蛋白质，支架蛋白和管道形成门户蛋白的多个副本。该项目将使用化学交联/质谱，氢/氘交换研究和突变分析与计算对接，以确定这种成核复合物的详细结构，并使用这些信息来化学稳定成核复合物。稳定的成核复合物将用于在本体溶液和单分子实验中接种组装反应，以探测向生长的衣壳添加亚基的序列和动力学，并获得对组装途径的分子水平理解。使用病毒作为范例的程序集和这种级别的详细描述目前对任何病毒都不可用。该研究项目本身采用了各种生物物理和生物化学工具，并作为研究生和本科生谁将进行实验的理想培训平台。最后，因为详细的分子途径是最好的赞赏和理解时，通过动画的装配路径由该项目定义将由艺术系和艺术史系的学生为外行观众动画暴露他们的前沿科学，同时允许他们完善自己的动画技能，并开发一个投资组合。