CONTROL OF DNA TOPOLOGY

DNA拓扑结构的控制

• 批准号: 6636188
• 负责人: Yuk-Ching Tse-Dinh
• 金额: $ 27.39万
• 依托单位: NEW YORK MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-04-01 至 2005-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6636188
• 关键词: DNA binding protein; DNA damage; DNA repair; DNA topoisomerases; Escherichia coli; active sites; bacterial DNA; bacterial proteins; catalyst; chemical cleavage; conformation; environmental stressor; enzyme complex; enzyme inhibitors; enzyme mechanism; enzyme structure; enzyme substrate; gene deletion mutation; genetic regulation; mutant; nucleic acid structure; protein structure function; proteolysis; site directed mutagenesis; stress proteins

Due to the recent emergence of pathogenic bacteria resistant to all antibiotics currently used, there is an urgent lead to develop new antibiotics against novel targets. Bacterial topoisomerase I is a promising new target for antibacterial therapy with lead compounds having MIC's of 4.0 mug against Staphylococcus aureus. E. coli topoisomerase I is the best studied example of bacterial topoisomerase I and share extensive homology with topoisomerase I from both gram-positive and gram- negative bacteria. Topoisomerase I targeting drugs that inhibit DNA religation would lead to cell killing in a mechanism similar to those of many drugs targeting bacterial DNA gyrase and human topoisomerases. Loss of topoisomerase I function may also affect the ability of the bacteria to respond to environmental challenges encountered in pathogenesis. The long term goals of this project include the elucidation of the mechanism, regulation and physiological roles of E. coli topoisomerase I, which would greatly aid the development of novel bacterial agents targeting this class of enzyme. The aims for this proposal include: 1. Structure-function analysis by different mutagenesis approaches to identify residues required for the individual steps of catalysis by E. coli topoisomerase I 2. Limited proteolysis and chemical cleavage of topoisomerase I in the absence and presence of DNA to identify sites of cleavage altered due to either enzyme conformational change or protection by DNA substrate. 3. Test of peptide sequences identified by panning as potential inhibitor of topoisomerase I 4. Study of the molecular basis of topoisomerase I involvement in bacterial adaptation to environmental challenges for survival.

由于近期对当前使用的所有抗生素具有抗性的致病细菌出现，因此紧急导致针对新靶标开发新的抗生素。 细菌拓扑异构酶I是抗菌治疗的有希望的新靶标，其铅化合物具有4.0杯抗金黄色葡萄球菌的MIC。 大肠杆菌拓扑异构酶I是细菌拓扑异构酶I的最佳研究示例，并与革兰氏阳性和革兰氏阴性细菌的拓扑异构酶I共享广泛的同源性。 拓扑异构酶I靶向抑制DNA宗教的药物将导致细胞杀死的机制，类似于靶向细菌DNA回旋酶和人拓扑异构酶的许多药物。 拓扑异构酶I功能的丧失也可能影响细菌应对发病机理遇到的环境挑战的能力。 该项目的长期目标包括阐明大肠杆菌拓扑异构酶I的机制，调节和生理作用，这将极大地有助于开发针对这种酶的新型细菌剂。 该提案的目的包括：1。通过不同的诱变方法进行结构 - 功能分析，以识别大肠杆菌拓扑异构酶催化的各个步骤I 2。有限的蛋白水解和拓扑异构酶I的化学分解，而在不存在DNA的情况下，dnna的化学分解和化学因素因素而变化而变化。 3。通过平移为拓扑异构酶I的潜在抑制剂鉴定的肽序列的测试4。研究拓扑异构酶I的分子基础I参与细菌适应生存环境挑战的细菌适应性。