Mechanistic Studies on a Viral DNA Packaging Machine

病毒DNA包装机的机理研究

• 批准号: 7060385
• 负责人: Carlos Enrique Catalano
• 金额: $ 29.47万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-10 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7060385
• 关键词: DNA virus; adenosine triphosphate; bacteriophage lambda; catalyst; chemical kinetics; chemical models; endodeoxyribonuclease; enzyme structure; genome; molecular assembly /self assembly; protein structure function; virus DNA; virus assembly; virus genetics; virus protein

Our long-range goal is to understand virus assembly at the molecular level. DNA packaging is a critical step in the assembly of many double-stranded DNA viruses, including poxvirus, adenovirus, herpesviruses, and many bacteriophages. Terminase enzymes are common to these viruses and function to package viral DNA into the capsid. Common mechanisms for genome packaging have been proposed for these all viruses. The process of genome packaging is unique to viruses, and thus represents an ideal target for antiviral therapy; however, the lack of mechanistic detail precludes a rational approach to drug design. Bacteriophage lambda presents an ideal system to study DNA packaging. Lambda terminase is a central component of an ordered series of packaging intermediates, and is an integral part of the packaging motor. The goal of this project is to define a coherent physical and kinetic model for the assembly of a viral DNA packaging motor. A mechanistic model for any complex biological process requires a description of the physical nature of the macromolecular complexes involved, a kinetic dissection of the catalytic activities required for the process, and a mechanism that clearly describes the linkage between catalysis, structure, and function. Unfortunately, virtually nothing is known about the physical properties of the packaging intermediates in lambda. Moreover, a mechanistic link between catalytic activity and function remains elusive, due in part to the dearth of structural information. This project seeks to (i) characterize the interactions responsible for specific assembly of the packaging motor on viral DNA, (ii) define the assembly state of the functional packaging motor, to (iii) characterize critical packaging intermediates, and (iv) characterize the activity of defined enzyme species to provide a direct link between stucture and function of termiase. A combined structural, biophysical, and kinetic approach will define critical aspects central to our understanding of the mechanism and enzymology of DNA packaging.

我们的长期目标是在分子水平上了解病毒的组装。 DNA 包装是许多双链 DNA 病毒组装的关键步骤，包括痘病毒、腺病毒、疱疹病毒和许多噬菌体。终止酶是这些病毒所共有的，其功能是将病毒 DNA 包装到衣壳中。已经为这些所有病毒提出了基因组包装的共同机制。 基因组包装过程是病毒所独有的，因此代表了抗病毒治疗的理想靶标；然而，缺乏机制细节阻碍了药物设计的合理方法。 λ 噬菌体是研究 DNA 包装的理想系统。 Lambda 终止酶是一系列有序包装中间体的核心组成部分，也是包装电机的组成部分。 该项目的目标是为病毒 DNA 包装马达的组装定义一个连贯的物理和动力学模型。任何复杂生物过程的机制模型都需要描述所涉及的大分子复合物的物理性质，对该过程所需的催化活性进行动力学剖析，以及清楚地描述催化、结构和功能之间联系的机制。不幸的是，人们对 lambda 包装中间体的物理性质几乎一无所知。此外，催化活性和功能之间的机制联系仍然难以捉摸，部分原因是缺乏结构信息。该项目旨在 (i) 表征病毒 DNA 上包装马达特定组装的相互作用，(ii) 定义功能性包装马达的组装状态，(iii) 表征关键的包装中间体，以及 (iv) 表征确定的酶种类的活性，以提供结构和功能之间的直接联系 终止酶。结构、生物物理和动力学相结合的方法将定义对我们理解 DNA 包装机制和酶学至关重要的关键方面。