Damage Sensing by the Bacterial Nucleotide Excision Repair Pathway

知识的优点。双链DNA是细胞的信息库，很容易被破坏。细胞已经进化出了几种途径来对这种损伤进行生化反应。其中之一是核苷酸切除修复（NER）途径，其特点是能够处理一系列化学上不同的损伤。在细菌中，NER的第一步是由三种蛋白质完成的：UvrA、UvrB和UvrC。大量的工作描述了中介NER的组件以及它们如何操作的细节。UvrA/UvrB集合识别损伤，并与UvrC等因素协同恢复原始序列。这种大型~300 kDa UvrA/UvrB损伤传感器和处理器的结构尚不清楚，这阻碍了实验了解其作用机制。该项目的目标是获得基于结构的核苷酸切除修复的理解。具体目的是解决以下问题：1)UvrA如何利用ATP感知受损的DNA？2) UvrA和UvrB如何协同处理DNA损伤？这项工作扩展了UvrA的结构和UvrA/UvrB集合的首次视图。了解NER通路的结构和功能是很重要的，因为它在维持遗传信息的完整性免受损伤以及在DNA复制、基因表达、进化和细胞过程（如凋亡、衰老和肿瘤发生）中的作用。更广泛的影响。在生物化学、细胞生物学和结构生物学方面开展了多学科综合教学和研究项目，针对大三、大四和博士生。讲座材料包括来自当前和过去研究的元素。此外，研究者还指导生物化学专业的本科生。研究者实验室培养了一大批有才华的大学生。这门科学是跨学科的，涉及分子生物学、生物化学、生物物理学和结构方法。研究结果发表在同行评议的期刊上。研究材料以几种方式提供给科学界，包括储存在蛋白质数据库中。

Intellectual Merits. Duplex DNA, the information repository of the cell, is easily damaged. Cells have evolved several pathways that mount biochemical responses to the presence of such damage. One of these is the nucleotide excision repair (NER) pathway, which is distinguished by the ability to process a chemically diverse set of damage. In bacteria, the first steps in NER are performed by three proteins: UvrA, UvrB, and UvrC. A large body of work has described the components that mediate NER and details of how they operate. The UvrA/UvrB ensemble recognizes damage and cooperates with UvrC and other factors to restore the original sequence. The structure of this large ~300 kDa UvrA/UvrB damage sensor and processor is unknown and this has stymied experiments to understand its mechanism of action. The goal of this project is to obtain a structure-based understanding of nucleotide excision repair. The specific aims address the following questions: 1) How does UvrA employ ATP to sense damaged DNA? and 2) How do UvrA and UvrB cooperate to process DNA damage? This work extends on the structure of UvrA and the first-ever view of the UvrA/UvrB ensemble. Understanding the structure and function of the NER pathway is important because of its central role in maintaining the integrety genetic information against damage and its role in DNA replication, gene expression, evolution and cellular processes such as apoptosis, senescence and tumorigenesis.Broader Impacts. The investigator developed an integrated multi-disciplinary teaching and research program in biochemistry, cell biology and structural biology targeting juniors, seniors and doctoral students. Lecture materials include elements from current and past research. In addition, the investigator tutors undergraduate biochemistry majors. A large group of talented undergraduates has trained in the investigators laboratory. The science is interdisciplinary and involves molecular biological, biochemical, biophysical, and structural approaches. Results are published in peer-reviewed journals. Research materials are made available to the scientific community in several ways, including depositions in the Protein Data Bank.