Virus Chromosome Structure: Role in Development

描述（由申请人提供）：λ噬菌体是研究大DNA病毒（包括疱疹病毒、痘病毒和腺病毒）的病毒体组装的极好模型系统。这些病毒组装空的蛋白质外壳，病毒染色体被包装在其中。此外，在许多类疱疹病毒和疱疹病毒的DNA包装过程中，病毒DNA的长的端对端聚合物在特定位点被切割以产生单位长度的分子。这种识别是由病毒包装蛋白与病毒DNA上的一组蛋白质结合位点的相互作用控制的。蛋白质-DNA相互作用如何协调包装是最好的理解。我们建议进一步定义这些DNA-蛋白质相互作用，这对病毒DNA识别具有广泛的意义。我们还试图了解一个装配催化剂，艾滋病的识别步骤的机制。虽然病毒DNA包装酶，末端酶的功能，已被广泛研究，壳的作用，特别是壳的门户顶点，没有。我们提出的门户网站在包装中的作用的实验，并试图定义门户网站的结合位点的末端酶。作为这项工作的一部分，我们计划研究参与壳组装的几种蛋白质的作用。这项工作将产生纯化的包装蛋白和组装适合结构分析。关于包装蛋白的结构信息对于理解丰富的遗传信息和帮助设计关于这些蛋白的功能的进一步研究是至关重要的。在任何病毒系统中，DNA如何移位到外壳中的机制都不清楚。我们提出了一系列的突变体，有缺陷的DNA包装，包括DNA易位的分子研究。我们还将研究末端酶移动DNA的能力，并对末端酶的功能结构域进行结构分析。

DESCRIPTION (provided by applicant): Bacteriophage Lambda is an excellent model system for studying virion assembly for the large DNA viruses, including the herpes, pox and adenoviruses. These viruses assemble empty protein shells into which the viral chromosome is packaged. In addition, during DNA packaging of many lambdoid phages and the herpes viruses, long end-to-end polymers of viral DNA are cut at specific sites to generate unit-length molecules.Viral DNA is selected for packaging from a DNA pool that also includes host sequences. This recognition is governed by the interactions of viral packaging proteins with a set of protein binding sites on the viral DNA. How protein-DNA interactions orchestrate packaging is best understood for . We propose to further define these DNA-protein interactions, which have broad implications for virus DNA recognition. We also seek to understand the mechanism of an assembly catalyst that aids recognition steps.While the functioning of the viral DNA packaging enzyme, terminase, has been extensively studied, the role of the shell, especially the shell's portal vertex, has not. We propose experiments on the portal's role in packaging, and seek to define the portal's binding site for terminase. As part of this work we plan to examine the roles of several proteins involved in shell assembly. This work will generate purified packaging proteins and assemblages suitable for structural analysis. Structural information about packaging proteins is crucial for understanding the wealth of genetic information and to assist in design of further studies on the functioning of these proteins.The mechanism of how DNA is translocated into the shell is not understood in any virus system. We propose molecular studies on a series of mutants that have defects in DNA packaging, including DNA translocation. We will also look at the ability of terminase to move DNA, and to pursue a structural analysis of functional domains of terminase.