Protein-protein interactions and structural switching of the bifunctional Chlamydia trachomatis protein, Scc4

双功能沙眼衣原体蛋白 Scc4 的蛋白质-蛋白质相互作用和结构转换

• 批准号: 10654269
• 负责人: Megan Alane Macnaughtan
• 金额: --
• 依托单位: LOUISIANA STATE UNIV A&M COL BATON ROUGE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2023-10-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10654269
• 关键词: Antibiotic Resistance; Bacteria; Bacterial Sexually Transmitted Diseases; Binding; Binding Proteins; Binding Sites; Biochemical; Biological; Biology; Blindness; COVID-19 pandemic; Cells; Chlamydia; Chlamydia trachomatis; Communicable Diseases; Complex; DNA-Directed RNA Polymerase; Data; Development; Disease; Dissociation; Drug Design; Drug Targeting; Enzymes; Funding; Gene Expression Regulation; Genetic; Genetic Transcription; Goals; Holoenzymes; In Vitro; Inclusion Bodies; Infant; Infection; Knowledge; Libraries; Ligand Binding; Ligands; Maps; Microbiology; Molecular; Molecular Chaperones; Molecular Conformation; Not Hispanic or Latino; Organism; Outcome; Pathogenesis; Pathway interactions; Pelvic Inflammatory Disease; Pharmaceutical Preparations; Pneumonia; Proteins; Public Health; Reporting; Reproductive Health; Research; Research Design; Resolution; Role; Sigma Factor; Site; Structural Models; Structure; Testing; Therapeutic; Type III Secretion System Pathway; United States; Virulence; Virulence Factors; Woman; Work; black women; design; experience; health disparity; in vivo; inhibitor; innovation; novel; novel strategies; pandemic disease; pathogenic bacteria; prevent; protein function; protein protein interaction; rational design; resistant strain; screening; small molecule; structural biology; three dimensional structure; tool; transcription factor; young woman

PROJECT SUMMARY The role of the bi-functional Chlamydia trachomatis protein, Scc4 (formerly Ct663), in regulating the type III se- cretion system (T3SS) and the essential, developmental cycle (between infectious elementary bodies and ac- tively dividing, reticulate bodies) is not well-understood at the molecular level. Scc4 is a unique protein that functions (i) as a T3SS chaperone with Scc1 to regulate secretion of CopN (an essential virulence factor) and (ii) as a transcription factor regulating 66-RNA polymerase holoenzyme. Based on progress made during the last funding period, the switching mechanism proposed for Scc4’s dual functions involves a conformational change in its 3-dimensional structure. Because Scc4 has two essential functions and is unique to C. tracho- matis, it is a novel target for developing anti-virulence drugs. To develop drugs targeting the C. trachomatis T3SS and developmental cycle, hit-compounds must first be identified and their effects on Scc4’s structure, protein-protein interactions, and functions characterized. The long-term goal of the proposed research is to de- velop drugs targeting Scc4’s functions, which would prevent the bacteria from spreading, likely curing C. tra- chomatis directly and certainly mitigating the development of antibiotic-resistant strains, when combined with current therapies. The overall objectives of this application are to increase our understanding of the conforma- tional changes and binding sites that regulate Scc4’s switching mechanism and protein-protein interactions. The central hypothesis is that a conformational switch in Scc4’s structure, induced by binding native ligands, regulates its dual activity. The rationale for the proposed research is that inhibitors to disrupt Scc4’s functions can be rationally designed, resulting in new approaches to treat C. trachomatis and new molecular tools to study the T3SS and developmental cycle. The central hypothesis and objectives of this application will be tested and attained by pursuing two specific aims: (1) identify small molecule ligands that bind or disrupt Scc4 and its T3SS complexes and (2) map the native protein- and small molecule-ligand binding sites on Scc4 and Scc4:Scc1 and identify allosteric effects. It is anticipated that these aims will yield the expected outcome of a structural model of ligand-binding sites on Scc4 and the Scc4:Scc1 complex from native ligands and hit-com- pounds. This outcome is expected to have an important positive impact because characterization of the protein binding sites and identification of small molecule ligands provide the information necessary to develop drugs targeting Scc4’s conformational switch or protein-protein interactions, fundamentally advancing the fields of structural biology and infectious disease biology. This contribution is significant because it is the first step in a continuum of research that is expected to lead to understanding Scc4’s dual functions at the atomic level and contribute to the treatment of the most common, sexually transmitted bacterial disease. The proposed research is innovative because the NMR structural and biochemical characterization of a unique bi-functional protein from C. trachomatis to target bacterial virulence as a therapeutic strategy represents a new and substantive departure from the status quo.

项目总结 双功能沙眼衣原体蛋白Scc4(以前的Ct663)在调节III型Se-2中的作用。 排泄系统(T3SS)和必要的发育周期(在有感染性的基本体和Acc之间)。 在分子水平上还没有被很好地理解。Scc4是一种独特的蛋白质， 功能(I)作为T3SS伴侣与Scc1一起调节COPN(一种重要的毒力因子)的分泌，以及 (Ii)作为转录因子调节66-RNA聚合酶全酶。根据在此期间取得的进展 上一次资助期，建造局局长S提出的双重功能转换机制涉及构象 它的三维结构发生了变化。因为ScC4有两个基本功能，并且是沙棘单胞菌所特有的。 Matis，它是开发抗毒力药物的新靶点。开发针对沙眼衣原体的药物 T3SS与发育周期、Hit-化合物的鉴定及其对ScC4‘S结构的影响， 蛋白质-蛋白质相互作用和功能表征。拟议研究的长期目标是消除 针对ScC4‘S功能的包膜药物，可以阻止细菌的传播，有可能治愈C.tra- 当与Chomatis结合时，可以直接并肯定地减缓抗药性菌株的发展 目前的治疗方法。本申请的总体目标是增加我们对一致性的理解-- 调控ScC4‘S开关机制和蛋白质-蛋白质相互作用的结构变化和结合位点。 中心假说是ScC4‘S结构中由天然配体结合引起的构象转换， 调节其双重活动。这项拟议研究的基本原理是，干扰Scc4‘S功能的抑制剂 可以进行合理的设计，从而产生治疗沙眼衣原体的新方法和新的分子工具 研究T3SS和发育周期。此应用程序的中心假设和目标将是 通过追求两个具体目标来测试和实现：(1)确定结合或破坏Scc4的小分子配体 和(2)定位了ScC4和ScC4上天然的蛋白质和小分子配体结合部位。 Scc4：Scc1和鉴定变构效应。预计这些目标将产生预期的结果 天然配体和HIT-COM的ScC4上的配体结合位点和ScC4：Scc1复合体的结构模型 磅。这一结果预计将产生重要的积极影响，因为对蛋白质的表征 小分子配体的结合位点和鉴定为开发药物提供了必要的信息 靶向ScC4的S构象开关或蛋白质-蛋白质相互作用，从根本上推进 结构生物学和传染病生物学。这一贡献意义重大，因为它是 有望在原子水平上理解ScC4的S双重功能的连续研究 有助于治疗最常见的性传播细菌疾病。拟议的研究 是创新的，因为一种独特的双功能蛋白质的核磁共振结构和生化特征 从沙眼衣原体到靶向细菌毒力作为一种治疗策略代表了一种新的实质性的 背离现状。