Mechanistic Studies on a DNA Packaging Machine

描述（由申请方提供）：核蛋白的组装 执行复杂生物功能的结构是一个共同的主题， 自然相关的例子包括核蛋白复合物， 染色体复制，DNA转录和基因组"包装"在许多 双链DNA（dsDNA）病毒。终止酶是多种酶共同的， dsDNA病毒组，包括疱疹病毒组。这些酶是一种 对基因组至关重要的一系列核蛋白复合物的组成部分 包装.所有已知的终止酶都具有ATP酶和核酸酶活性 在包装过程中起着重要作用。校长 研究人员和他的小组对这种生物化学性质感兴趣， 包装机械，特别是末端酶的酶学。 本提案中描述的研究旨在了解分子机制 基因组的包装。该酶具有位点特异性 核酸酶和ATP酶催化活性协同工作以包装病毒 DNA.描述包装途径的可行模型已经开发出来。许多 然而，包装途径的各个方面仍然模糊不清， 机械的严格研究的目的是提供一个机制的基础， 这些催化活动之间的微妙相互作用，以及它们在 核蛋白包装中间体的组装和稳定性。生化 和酶动力学研究旨在直接探测催化 酶的作用机制，并确定核蛋白的催化作用 复杂的装配和功能。虽然机械细节可能有所不同，但数据 从这些实验中得到的DNA可以用于模拟DNA包装， 双链DNA病毒，包括医学相关的腺病毒， 疱疹病毒群。此外，这种酶与 参与DNA复制的复杂核蛋白机器， 转录。了解这种包装的催化性能 这台机器可以通过以下方式深入了解DNA操纵的一般机制： 大型多蛋白酶复合物。

DESCRIPTION (provided by the applicant): The assembly of nucleoprotein structures that perform complex biological functions is a common theme in nature. Relevant examples include the nucleoprotein complexes involved in chromosomal replication, DNA transcription, and genome "packaging" in many double-stranded DNA (dsDNA) viruses. Terminase enzymes are common to a diverse group of dsDNA viruses, including the herpesvirus groups. These enzymes are an integral part of a series of nucleoprotein complexes critical to genome packaging. All of the known terminases possess ATPase and nuclease activities that play an important role in the packaging process. The principal investigator and his group are interested in the biochemical properties of the packaging machinery, and specifically the enzymology of the terminase enzymes. Studies described in this proposal seek to understand the molecular mechanism of genome packaging by lambda terminase. The enzyme possesses site-specific nuclease and ATPase catalytic activities that work in concert to package viral DNA. Viable models describing the packaging pathway have been developed. Many aspects of the packaging pathway remain obscure, however, and most lack mechanistic rigor. Studies are designed to provide a mechanistic basis for the delicate interplay between these catalytic activities, and their role in the assembly and stability of nucleoprotein packaging intermediates. Biochemical and enzyme kinetic studies are designed to directly probe the catalytic mechanism of the enzyme, and to define the role of catalysis in nucleoprotein complex assembly and function. While mechanistic details may differ, the data derived from these experiments may be used to model DNA packaging by other double-stranded DNA viruses, including the medically relevant adenovirus and herpesvirus groups. Furthermore, this enzyme shares mechanistic similarities to the complex nucleoprotein machines involved in DNA replication and transcription. An understanding of the catalytic properties of this packaging machine may yield insight into the general mechanisms of DNA manipulation by large multiprotein enzyme complexes.