Mismatch Repair Interactions

错配修复相互作用

• 批准号: 7152387
• 负责人: PAUL LAWRENCE MODRICH
• 金额: $ 4.91万
• 依托单位: UNIVERSITY OF CALIF-LAWRENC BERKELEY LAB
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7152387
• 关键词: DNA; proteins

The Project (Mismatch Repair Interactions) integrates into the SBDR Program Project by focusing upon early responses to mutagenic mispaired bases and DNA adducts, including adducts made by chemotherapeutic agents. Mismatch repair is a major contributor to genome stability; defects in the mammalian pathway are associated with a strong predisposition to tumor development and inherited mutations in mismatch repair genes underlie one of the most prevalent inherited cancer susceptibility syndromes known. Despite the importance of this system in avoiding mutation, our understanding of its molecular nature is limited. The goals of this project are to establish the conformations and structures of multi-protein and multi-protein-DNA complexes that are the key intermediates in triggering the MutSa- and MutLa-dependent responses to mismatched base pairs and certain types of DNA damage. To accomplish this, our aims are four-fold: (1) The conformations and dynamics of multi-protein and multi-protein DNA assemblies involved in the initiation step of mismatch repair will be addressed by small angle X-ray scattering. These and other structural studies will exploit the high temporal resolution of the Structural Cell Biology (SCB) Synchrotron Beamline and the SCB Core. (2) The molecular basis for the recognition of base-base mispairs, insertion/deletion mispairs, and damaged DNA substrates will be addressed by X-ray crystallography. (3) Since the initiation of mismatch repair depends on assembly of multi-protein-DNA complexes (MutSa.MutLa.PCNA.DNA in the eukaryotic reaction) these multi-protein and multi-protein-DNA assemblies will be examined using X-ray crystallography. (4) The structural studies above will reveal residues at protein-protein interfaces as well as those that may be involved in conformational transitions; the significance of these residues will be subjected to biological validation by analysis of the phenotypic consequences of genetic alteration of these residues and by examination of selected mutant proteins at the biochemical level.

该项目（错配修复相互作用）通过关注早期问题整合到 SBDR 计划项目中 对诱变错配碱基和 DNA 加合物（包括化疗药物产生的加合物）的反应 代理。错配修复是基因组稳定性的主要贡献者；哺乳动物途径的缺陷是 与肿瘤发展的强烈倾向和错配修复的遗传突变有关 基因是已知最普遍的遗传性癌症易感性综合征之一。尽管 虽然该系统在避免突变方面的重要性，但我们对其分子性质的理解是有限的。这 该项目的目标是建立多蛋白和多蛋白-DNA的构象和结构 复合物是触发 MutSa 和 MutLa 依赖性反应的关键中间体 碱基对不匹配和某些类型的 DNA 损伤。为了实现这一目标，我们的目标有四个：(1) 参与启动的多蛋白和多蛋白 DNA 组装体的构象和动力学 错配修复步骤将通过小角度 X 射线散射来解决。这些和其他结构 研究将利用结构细胞生物学 (SCB) 同步加速器光束线的高时间分辨率 和 SCB 核心。 (2)识别碱基错配、插入/缺失的分子基础 错配和受损的 DNA 底物将通过 X 射线晶体学来解决。 （三）自实施以来 错配修复依赖于多蛋白-DNA 复合物的组装（MutSa.MutLa.PCNA.DNA 真核反应）这些多蛋白和多蛋白-DNA 组装体将使用 X 射线进行检查 晶体学。 (4) 上述结构研究将揭示蛋白质-蛋白质界面上的残基以及 那些可能参与构象转变的；这些残基的重要性将受到 通过分析这些残基遗传改变的表型后果进行生物学验证 并通过在生化水平上检查选定的突变蛋白。