Biochemical Analysis of Type II DNA Topoisomerases

II 型 DNA 拓扑异构酶的生化分析

• 批准号: 6852702
• 负责人: JAMES M BERGER
• 金额: $ 29.69万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6852702
• 关键词: DNA; DNA gyrase; X ray crystallography; adenosine triphosphate; antineoplastics; conformation; drug interactions; enzyme mechanism; enzyme structure; enzyme substrate complex; molecular cloning

DESCRIPTION (provided by applicant): The long-term objective of this proposal is to structurally define type II topoisomerase function and drug inhibition mechanisms. Type II topoisomerases are a ubiquitous class of proteins that use ATP to actively transport one DNA duplex through another. This reaction maintains appropriate levels of DNA supercoiling and resolves lethal chromosome tangles in the cell. Eukaryotic type II topoisomerases are also exploited by certain inhibitors that are frontline clinical therapies for cancer. The focus of this proposal is on eukaryotic topoisomerase II and archaeal topoisomerase VI, two representative members of type IIA and liB topoisomerases, respectively. The specific aims of the research are as follows: 1. To understand how type II topoisomerases physically switch between conformational states. 2. To define how type II topoisomerases interact with and utilize reaction substrates. 3. To determine how certain anticancer agents bind to and inhibit eukaryotic topoisomerase II Although a general framework exists for understanding type II topoisomerase function, significant gaps remain. A detailed structural description of type II topoisomerase mechanism coupled with biochemical validation, will illuminate critical aspects of these enzymes' function. The studies outlined here will define the physical events by which type II topoisomerases catalyze the ATP-dependent passage of one DNA segment through another and by which anticancer inhibitors subvert enzyme function. Data resulting from such efforts broadly impact a number of important scientific research fronts, from understanding how a molecular machine maintains chromosome topology to dissecting the molecular basis of various chemotherapeutic treatments.

描述（由申请人提供）： 该建议的长期目标是在结构上定义II型拓扑异构酶功能和药物抑制机制。 II型拓扑异构酶是一种普遍存在的蛋白质类别，使用ATP积极将一种DNA双链体通过另一个DNA双链体运输。该反应保持适当水平的DNA超串联，并解决细胞中致命的染色体缠结。真核II型拓扑异构酶也被某些抑制剂（是癌症的一线临床疗法）所利用。该建议的重点是真核拓扑异构酶II和古细胞拓扑异构酶VI，分别是IIA型和LIB拓扑异构酶的两个代表成员。 研究的具体目的如下： 1。了解如何在构象状态之间进行物理切换。 2。定义II型拓扑异构酶如何与反应底物相互作用并使用。 3。确定某些抗癌剂如何与真核拓扑异构酶II结合并抑制 尽管存在用于理解II型拓扑异构酶函数的一般框架，但仍然存在明显的差距。 II型拓扑异构酶机制和生化验证的详细结构描述将阐明这些酶功能的关键方面。此处概述的研究将定义物理事件，该物理事件通过哪些II型拓扑异构酶催化一个DNA段通过另一个段的ATP依赖性通过，并通过其抗癌抑制剂颠覆酶功能。这种努力产生的数据广泛影响了许多重要的科学研究方面，因为了解分子机器如何保持染色体拓扑以剖析各种化学治疗的分子基础。