Structural Biochemistry of DNA Base Repair

DNA 碱基修复的结构生物化学

• 批准号: 6682156
• 负责人: John A. Tainer
• 金额: $ 53.33万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6682156
• 关键词: DNA damage; DNA repair; N glycosidase; Saccharomyces; acetylation; active sites; alkylation; conformation; crystallization; endonuclease; enzyme activity; enzyme structure; intermolecular interaction; lyase; model design /development; molecular assembly /self assembly; physical model; protein protein interaction; site directed mutagenesis

DESCRIPTION (provided by applicant): Genomic integrity depends upon the efficient repair of DNA base damage that would otherwise cause mutagenic and cytotoxic effects. The proposed integrated and synergistic structural (Scripps) and biochemical (SUNY) characterizations aim to define the structural biochemistry for DNA base repair (BR) by comparative studies of protein: DNA and protein: protein complexes acting in initiation of the major base damage response systems. We will evaluate DNA Base Excision Repair (BER) enzymes, which initiate repair pathways by recognizing and removing damaged bases and abasic sites, in concert with studies on direct base damage reversal by single enzymes and on other mechanisms for removal of non-classical bases from the nucleotide pool. We will address three fundamental hypotheses: 1) the self-assembly of DNA base repair complexes involves experimentally definable conformational controls, 2) initial committed steps in multi-step repair pathways generate stable intermediates or product complexes that create platforms influencing subsequent steps, and 3) direct damage reversal enzymes are coordinated by binding other components rather than by forming stable complexes with DNA products. Our pyramid approach involves beginning with multiple target enzymes in each aim and then progressively focusing on the most informative proteins. This strategy of pursuing multiple enzymes for each DNA BR class is thus aimed at efficiently achieving a unified understanding. We wiII be guided in the optimization of target complexes for each of the five Specific Aims by the rapidly emerging genetic and biochemical results on BR, including those from our strategically chosen collaborators. This research will test unifying hypotheses relevant to base repair enzyme activities and functions in genomic integrity, including the overall proposition that repair pathway progression and coordination are an emergent property of the structural chemistry for individual protein: damaged DNA base complexes. Comparative experiments among BR enzymes and species wiII test hypotheses from individual structures and better characterize structural motifs and chemical mechanisms in the most timely and cost effective fashion. This research aims to provide fundamental knowledge on DNA BR related complexes that will define their roles in the regulation of genome fidelity and the mechanisms w hereby loss of the functions of these coordinated complexes may lead to inheritable genetic defects and the initiation of cancer.

描述（由申请人提供）：基因组完整性取决于DNA碱基损伤的有效修复，否则会导致诱变和细胞毒性作用。提出的综合和协同结构（SCRIPP）和生化（SUNY）表征旨在通过蛋白质的比较研究来定义DNA碱修复（BR）的结构生物化学：DNA和蛋白质：蛋白质复合物作用于启动主要碱基损伤响应系统的蛋白质复合物。我们将评估DNA碱基切除修复（BER）酶，该酶通过识别和去除受损的碱基和无碱性位点来启动修复途径，并与单个酶直接碱损伤逆转以及其他机制的研究以及其他从核苷酸池中删除非经典基地的机制。我们将解决三个基本假设：1）DNA基础修复络合物的自组装涉及实验可定义的构象控制，2）在多步维修途径中的初始步骤产生稳定的中间体或产品复合物，这些步骤或产生平台创建了影响后续的平台，并且3）由损坏逆转互动的组合而不是由其他组成的组合构造，而不是由其他组成的组合组成。我们的金字塔方法涉及从每个目标中的多种靶酶开始，然后逐步专注于最有用的蛋白质。因此，为每个DNA BR类追求多种酶的策略旨在有效地实现统一的理解。我们将通过对BR的快速新兴遗传和生化结果（包括我们战略选择的合作者的遗传和生化结果）的五个特定目标来优化目标复合物。这项研究将测试与基础修复酶活性和基因组完整性中功能有关的统一假设，包括整体主张修复途径进展和协调是对个体蛋白质结构化学的新兴特性：受损的DNA碱基复合物。 BR酶和物种WIII测试假设之间的比较实验，以最及时，最具成本效益的方式更好地表征结构基序和化学机制。这项研究旨在提供有关与DNA BR相关的复合物的基本知识，这些知识将定义其在基因组忠诚度调节中的作用以及这些协调复合物功能的机制可能会导致可遗传的遗传缺陷和癌症的启动。