DNA glycosylases involved in interstrand crosslink repair and antibiotic self-resistance

DNA糖基化酶参与链间交联修复和抗生素自身抗性

• 批准号: 2341288
• 负责人: Brandt Eichman
• 金额: $ 130万
• 依托单位: Vanderbilt University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-04-01 至 2028-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2341288&HistoricalAwards=false
• 关键词: DNA; glycosylases; involved; interstrand; crosslink

DNA is chemically altered, or damaged, by its interaction with molecules found in the cell and in the environment. All organisms contain enzymes that repair damaged DNA to protect the integrity of the genetic information. This research project will determine how a newly discovered DNA repair enzyme found in bacteria works to repair damage created by specific toxins, which some bacteria produce as defense mechanisms. Because of their toxicity, these bacteria-derived toxins often have antimicrobial and antitumor properties, making them important in agriculture, industry, and medicine. The project will benefit society by providing 1) undergraduate and graduate students with hands-on experience in methods used to determine atomic structures of proteins that are important for discovery and innovation in biotechnology, 2) summer research opportunities to undergraduates of Fisk University, a nearby historically black college/university, 3) teaching and mentoring opportunities for all trainees, 4) exposure of high school students interested in STEM to biomedical research, and 5) community outreach. These activities are facilitated through a collaborative and inclusive training environment at the intersection of the College of Arts and Science and the School of Medicine at Vanderbilt University.Interstrand DNA crosslinks (ICLs) are among the most cytotoxic forms of DNA damage because they covalently tether the two DNA strands and therefore interfere with DNA replication and transcription. A new ICL repair pathway was recently discovered in both eukaryotes and prokaryotes, in which a DNA glycosylase liberates one of the crosslinked nucleobases from the DNA backbone. The bacterial ICL glycosylases belong to a family of uncharacterized proteins prevalent in antibiotic producers and pathogens. The PI’s laboratory discovered that E. coli YcaQ initiates an ICL repair pathway by unhooking chemically diverse ICLs, and characterized a related enzyme (AlkZ) that provides Streptomyces with self-resistance to the toxicity of one of its natural products, azinomycin B, by unhooking resulting azinomycin B-ICLs. The long-term goals of this project are to elucidate the ICL repair pathway in bacteria, to understand how microbes utilize DNA repair to protect against genotoxic natural products in nature and within the microbiome, and to discover new genotoxic agents with beneficial applications. The short-term goals are to understand the molecular basis for ICL unhooking by YcaQ and for the specificity of AlkZ-related enzymes for highly functionalized crosslinking and intercalating natural products, and to characterize the bioactivities of putative genotoxins. A multidisciplinary approach integrating structural biology, biochemistry, genetics, cell biology, and metabolomics will be employed to achieve these goals.This project is supported by the Genetic Mechanisms program in the Division of Molecular and Cellular Biosciences/Directorate for Biological Sciences and the Chemistry of Life Processes program in the Division of Chemistry/Directorate for Mathematical and Physical Sciences.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

DNA 通过与细胞和环境中的分子相互作用而发生化学改变或损坏。所有生物体都含有修复受损 DNA 的酶，以保护遗传信息的完整性。该研究项目将确定新发现的 DNA 修复方式。细菌中发现的酶可以修复某些细菌作为防御机制产生的特定毒素造成的损伤，这些细菌衍生的毒素通常具有抗菌和抗肿瘤特性，使其在农业、工业和医学项目中发挥重要作用。将通过提供造福社会1) 在用于确定蛋白质原子结构的方法方面具有实践经验的本科生和研究生，这对于生物技术的发现和创新非常重要，2) 为附近历史悠久的黑人学院/大学菲斯克大学的本科生提供暑期研究机会，3 ) 为所有学员提供教学和指导机会，4) 让对 STEM 感兴趣的高中生接触生物医学研究，以及 5) 通过艺术与科学学院交叉点的协作和包容性培训环境促进这些活动。和范德比尔特大学医学院。链间 DNA 交联 (ICL) 是最具细胞毒性的 DNA 损伤形式之一，因为它们共价连接两条 DNA 链，因此干扰 DNA 复制和转录。最近在两种真核生物中发现了一种新的 ICL 修复途径。和原核生物，其中 DNA 糖基化酶从 DNA 主链中释放交联的核碱基。细菌 ICL 糖基化酶属于PI 实验室发现，大肠杆菌 YcaQ 通过解开化学上不同的 ICL 来启动 ICL 修复途径，并鉴定了一种相关酶 (AlkZ)，该酶使链霉菌对抗生素的毒性具有自我抵抗力。该项目的长期目标是阐明其天然产物阿齐霉素 B。细菌中的 ICL 修复途径，了解微生物如何利用 DNA 修复来防御自然界和微生物组内的基因毒性天然产物，并发现具有有益应用的新基因毒性剂。短期目标是了解 ICL 脱钩的分子基础。 YcaQ 和 AlkZ 相关酶对高功能化交联和嵌入天然产物的特异性，并表征假定的基因毒素的生物活性 一种整合结构生物学的多学科方法，将采用生物化学、遗传学、细胞生物学和代谢组学来实现这些目标。该项目得到了分子和细胞生物科学部/生物科学理事会的遗传机制计划和生命过程化学计划的支持化学/数学和物理科学理事会。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。