STRUCTURE OF DNA POLYMERASE

DNA聚合酶的结构

• 批准号: 3568418
• 负责人: WAYNE F ANDERSON
• 金额: $ 6.16万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-01 至 1996-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3568418
• 关键词: DNA; DNA directed DNA polymerase; RNA directed DNA polymerase; X ray crystallography; active sites; chemical binding; chemical models; computer program /software; computer simulation; crystallization; enzyme mechanism; enzyme structure; enzyme substrate complex; exonuclease; extrachromosomal DNA; ionic bond; isozymes; model design /development; nucleic acid sequence; nucleic acid structure; oligonucleotides; protein sequence; protein structure function; site directed mutagenesis; structural biology

The replication and repair of genetic material is essential for all organisms and the survival of each species requires that this be done in a timely and accurate fashion. The synthesis of DNA is a complex, highly regulated reaction catalyzed by DNA polymerases. Damage to the DNA caused by chemical or physical agents causes premutagenic lesions. The biological effects of mutagens or DNA damaging agents depend on both the efficiency of DNA repair and what occurs when a DNA polymerase encounters the DNA lesion. A lesion that blocks replication is potentially a lethal event unless it can be repaired or bypassed. At the same time, translesion replication by a DNA polymerase may lead to mutation. Since chemical carcinogenesis is generally associated with adducts or damaged sites in the DNA, the study of DNA polymerases is highly relevant to an understanding of carcinogenesis. The long range goal of the proposed research is a molecular understanding of DNA replication. Attaining this goal requires a knowledge of the relationship between DNA polymerase structure and its functions. These functions include the binding of primer and template DNA, binding of dNTP substrates, the catalysis of polymerization, mechanisms for improving the fidelity of replication and mechanisms for increasing processivity. At the present time our understanding of these processes is limited by the complete lack of structural information on the class B, or alpha-type, polymerases that include the eukaryotic replicative polymerases and by the very limited structural data on polymerases in general. The primary aim of the proposed research is the determination of the three dimensional structure of the E. coli DNA polymerase II through the use of X-ray crystallographic techniques. DNA polymerase II is induced by DNA dazzle as part of the SOS response and appears to have a role in DNA repair. DNA polymerase II is related to the eukaryotic a type replicative polymerases rather than the better characterized E. coli DNA polymerase I, consequently this enzyme is of particular interest.

遗传物质的复制和修复对所有人都至关重要 生物体和每个物种的生存需要在 及时准确的时尚。 DNA的合成是一个复杂、高度复杂的过程 DNA聚合酶催化的调节反应。对DNA造成的损伤 由化学或物理因素引起的诱变前病变。生物的 诱变剂或 DNA 损伤剂的效果取决于效率 DNA 修复以及当 DNA 聚合酶遇到 DNA 时会发生什么 病变。阻止复制的病变可能是致命事件 除非可以修复或绕过。同时，穿越 DNA聚合酶的复制可能导致突变。由于化学 致癌作用通常与加合物或受损位点有关 DNA 聚合酶的研究与 DNA 高度相关 了解致癌作用。 拟议研究的长期目标是分子理解 DNA 复制。实现这一目标需要了解 DNA聚合酶结构及其功能之间的关系。 这些 功能包括引物和模板DNA的结合、dNTP的结合 底物、聚合催化、改善机制 复制保真度和提高持续性的机制。在 目前我们对这些过程的理解仅限于 完全缺乏 B 类或 alpha 型的结构信息， 聚合酶，包括真核复制聚合酶和 一般而言，聚合酶的结构数据非常有限。 本研究的主要目的是确定三个 通过使用大肠杆菌 DNA 聚合酶 II 的空间结构 X 射线晶体学技术。 DNA 聚合酶 II 由 DNA 诱导 眩晕是 SOS 反应的一部分，似乎在 DNA 中发挥作用 维修。 DNA聚合酶II与真核a型复制相关 聚合酶而不是特征更好的大肠杆菌 DNA 聚合酶 I， 因此，这种酶特别令人感兴趣。