Biochemical Properties of gpNu1, a Phage Lambda Protein Required for Viral Assembly

1. casino DNA在空的预先形成的衣壳中的包装通过有序的核蛋白中间体的进展进行，需要终止酶，一种所有双链DNA噬菌体共有的酶。 酶亚基gpNu 1和gpA组装到多元件DNA结合位点上，产生核蛋白复合物，从多联体切除单个基因组并将其插入衣壳。本研究探讨，在分子水平上，λ噬菌体1 gpNu 1蛋白的生物化学和生物物理特性的合作组装和不寻常的稳定性所涉及的核蛋白中间体负责。目的是了解gpNu 1自缔合相互作用和gpNu 1 gpA蛋白质蛋白质相互作用的组装和核蛋白复合物的稳定性的组装至关重要的作用。 这些实验的目的是提供一个详细的了解gpNu 1的自关联和合作结合到DNA之间的热力学联系，并随后组装的gpA和催化能力的基因组包装复合物。 本研究还试图定义gpNu 1多肽内的功能结构域，这些结构域负责观察到的gpNu 1寡聚化，gpNu 1 gpA相互作用，以及与DNA的合作结合。由于末端酶是常见的许多双链DNA病毒，这项研究的结果可能普遍适用于其他病毒的装配和包装机制的理解。 2.多种生物过程需要将多种蛋白质组装到细胞和/或病毒染色体内的特定位点上。 许多这些复合物最初组装成稳定的中间体，随后转化为高度移动的生物机器。 精细的核蛋白（DNA和蛋白质）复合物负责关键的生物过程，包括染色体的复制，信使RNA的合成和感染性病毒的组装。 本研究旨在阐明病毒在细胞内组装的过程和病毒染色体包装的复杂过程，特别是在参与终止酶，多蛋白质机器插入病毒染色体在噬菌体λ的保护性蛋白质外壳，一种病毒感染细菌E。杆菌这种酶是许多双链DNA病毒所共有的，是一系列有序的核蛋白复合物的组成部分，这些核蛋白复合物对病毒组装至关重要。 实验进行检查的生化和生物物理特性的gpNu 1，噬菌体1包装蛋白，这是负责组装和不寻常的稳定性的核蛋白中间体参与病毒染色体包装。 重要的是，来自这些研究的数据将进一步深入了解驱动稳定核蛋白复合物组装的基本原理，这些核蛋白复合物参与对病毒和细胞复制至关重要的各种生物过程。

Catalano 9728550 1. Technical Packaging of DNA within an empty pre-formed capsid proceeds through an ordered progression of nucleoprotein intermediates requires terminase, an enzyme common to all of the double-stranded DNA bacteriophages. The enzyme subunits, gpNu1 and gpA, assemble onto a multi-element DNA binding site generating a nucleoprotein complex, excising a single genome from the concatamer and inserting it into the capsid. This study examines, at the molecular level, the biochemical and biophysical properties of the lambda phage 1 gpNu1 protein which are responsible for the cooperative assembly and unusual stability of the nucleoprotein intermediates involved. The aims are to understand the roles of gpNu1 self-association interactions and gpNu1 gpA protein protein interactions in the assembly and stability of the nucleoprotein complexes critical to the assembly. The experiments are designed to provide a detailed understanding of the thermodynamic linkages between gpNu1 self-association and cooperative binding to DNA, and to the subsequent assembly of gpA and a catalytically competent genome packaging complex. This study also seeks to define functional domains within the gpNu1 polypeptide which are responsible for the observed oligomerization of gpNu1, for gpNu1 gpA interactions, and for cooperative binding to DNA. Since the terminase enzyme is common to many double-stranded DNA viruses, findings from this study may be generally applicable to the understanding of other viral assembly and packing mechanisms. 2. Non-Technical A variety of biological processes require the assembly of multiple proteins onto specific sites within the chromosomes of cells and/or viruses. Many of these complexes initially assemble as stable intermediates which are subsequently transformed into highly mobile biological machines. Elaborate nucleoprotein (DNA and protein) complexes are responsible for critical biological processes including the replication of chromosomes, the synthesis of messenger RNA, and the assembly of infectious viruses. This study is to elucidate the process of viral assembly within the cell and the complex process of viral chromosome packaging, specifically in the involvement of the terminase enzyme, the multi-protein machines which insert the viral chromosome within a protective protein shell in bacteriophage lambda, a virus which infects the bacteria E. coli. This enzyme, which is common to many double-stranded DNA viruses, is an integral part of an ordered series of nucleoprotein complexes which are critical to viral assembly. Experiments are carried out to examine the biochemical and biophysical properties of gpNu1, a phage l packaging protein, which are responsible for the assembly and unusual stability of the nucleoprotein intermediates involved in viral chromosome packaging. Importantly, the data derived from these studies will additionally yield insight into the basic principles driving the assembly of stable nucleoprotein complexes involved in a variety of biological processes critical to both viral and cellular replication.