CRYSTAL STRUCTURE OF DNA REPLICATION PROTEINS

DNA 复制蛋白的晶体结构

• 批准号: 6544644
• 负责人: JOHN KURIYAN
• 金额: $ 18.61万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-01-01 至 2002-12-09
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6544644
• 关键词: Archaea; DNA directed DNA polymerase; DNA replication; Escherichia coli; X ray crystallography; adenosinetriphosphatase; bacterial proteins; bacteriophage T4; cell cycle proteins; crystallization; enzyme mechanism; exonuclease; nucleic acid structure; oncoprotein p21; proliferating cell nuclear antigen; protein purification; protein structure; replicase; virus protein

DESCRIPTION (Adapted from abstract): X-ray crystallography will be used to study the structures of replicases (polymerase, sliding clamp protein, and complex that loads clamp onto DNA). Completed work has shown that the processivity factors from bacteria (beta subunit), eukaryotes (PCNA), and bacteriophage T4 (gene 45 protein) are ring-shaped proteins that share a commo architecture. These provide a sliding platform to which the polymerase machinery is tethered. Each of these replicases contains a multi-subunit clamp-loader. An active clamp-loader complex from E. coli (gamma, delta, and delta prime subunits) has been crystallized. An alternative strategy is to use proteins from thermophilic organisms. Several subunits of the replicase of the eubacterium Thermus thermophilis (T. th.) have been cloned. The DNA-dependent ATPase subunit of the clamp-loader of T. th. (gamma subunit) has been crystallized. The structure of the DNA polymerase/exonuclease from an extreme archaebacterial thermophile Desulfurucoccus tok, which is homologous to the PCNA-dependent mammalian DNA polymerases delta and epsilon, will be determined from crystals that diffract to 2.4 A. Although DNA replicases from various organisms share a common mechanistic framework, the protein components are quite divergent in sequence. The structural information resulting from this work may set the stage for structure-based design of replicase inhibitors with potential for high specificity.

描述（根据摘要改编）：X射线晶体学将用于 研究复制酶的结构（聚合酶，滑动夹具蛋白和 将夹在DNA上的复合物。 完成的工作表明 细菌（β亚基），真核生物（PCNA）和 噬菌体T4（基因45蛋白）是环形蛋白，共享 欧盟架构。 这些提供了一个滑动平台 聚合酶机械是束缚的。 这些复制酶中的每一个都包含一个 多支付夹具加载器。 大肠杆菌的活跃夹具装载机复合物 （伽玛，三角洲和三角洲素数亚基）已结晶。 一个 替代策略是使用嗜热生物的蛋白质。 嗜热菌的复制酶的几个亚基 （T. Th。）已被克隆。 DNA依赖性ATPase亚基 T. Th的夹具加载器。 （伽玛亚基）已结晶。 这 DNA聚合酶/外切核酸酶的结构，来自极端的考古学 嗜热氟氟曲霉桌子，它与PCNA依赖性同源 哺乳动物DNA聚合酶三角洲和Epsilon将从 衍射为2.4 A的晶体，尽管来自各种的DNA复制酶 生物具有共同的机械框架，蛋白质成分是 序列上的不同。 由此产生的结构信息 工作可能为基于结构的复制酶抑制剂设计奠定了基础 具有高特异性的潜力。