Mechanistic Studies on a DNA Packaging Machine

描述(申请人提供)：核蛋白的组装 执行复杂生物功能的结构是 大自然。相关的例子包括核蛋白复合体 染色体复制、DNA转录和基因组“打包” 双链DNA(DsDNA)病毒。终端酶是不同种类的 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体的组成部分 包装。所有已知的末端酶都具有ATPase和核酸酶活性 在包装过程中起着重要作用的产品。校长 研究人员和他的团队对这种生物化学特性很感兴趣 包装机械，特别是终端酶的酶学。 这项建议中描述的研究试图了解分子机制。 由lambda终止酶包装的基因组。这种酶具有位点特异性。 核酸酶和ATPase催化活性协同作用包装病毒 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，而且大多数缺乏 机械上的严谨。研究的目的是为 这些催化活性之间微妙的相互作用，及其在 核蛋白包装中间体的组装和稳定性。生化 酶动力学研究的目的是直接探测催化 酶的作用机制，以及确定催化在核蛋白中的作用 复杂的装配和功能。虽然机械细节可能有所不同，但数据 从这些实验中得出的结果可以用来对DNA包装进行建模 双链DNA病毒，包括与医学相关的腺病毒和 疱疹病毒群。此外，这种酶在机理上与 参与DNA复制和复制的复杂核蛋白机器 抄写。对这种包装的催化性能的理解 机器可以通过以下方式深入了解DNA操纵的一般机制 大的多蛋白酶复合体。

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.