Phosphorylated Carbohydrate Transport Across the Bacterial Cell Envelope

磷酸化碳水化合物跨细菌细胞膜的运输

• 批准号: RGPIN-2018-06546
• 负责人: Moraes, Trevor
• 金额: $ 4.23万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=690802
• 关键词: Phosphorylated; Carbohydrate; Transport; Across; Bacterial

Bacteria depend on the acquisition of a diverse set of nutrients from their hosts to engage in successful growth, colonization or pathogenesis. Commensal and/or pathogenic bacteria compete with host cells for substrates ranging from metals to vitamins. As this competition can influence the outcome of infection, pathogens have developed a variety of nutrient uptake mechanisms to increase their competitiveness and hence their ability to colonize and productively infect their hosts. The long-term objective of my research programs is to elucidate the molecular basis of bacterial nutrient uptake by isolating membrane proteins and performing atomic resolution structural and functional characterization using a unique combination of X-ray crystallography and other biophysical tools such as microscale thermophoresis and biolayer interferometry, surface plasmon resonance and isothermal titration calorimetry.***My NSERC research focuses on nutrient uptake mechanisms via the binding-protein dependent transporters (BPDTs), which target diverse ligands such as metal ions, amino acids and sugars and are recognized as virulence determinants in many bacterial infections. My short-term objectives outlined in this proposal are to decipher the mechanism of AfuABC a binding protein dependent transporter that we determined is responsible for active uptake of phosphorylated carbohydrates. Our structural insights will provide the molecular basis of nutrient scavenging from the host and how these bacteria compete for nutrients in complex environments.***Aim 1. Characterize the identify AfuABC homologs and paralogs for substrate specificity and transport.***Aim 2. Dissect the mechanism of transport of phospho-sugars by AfuABC using crystal structures, growth assays and biomolecular interactions to probe the interaction between the AfuA and AfuBC components of the uptake system. ***Aim 3. Determine the role of transporters in the pathogenesis and the source of the substrates that are acquired by these bacteria.***These aims will lead to a critical understanding of phospho-sugar nutrient acquisition by bacterial pathogens and how this process provides a competitive advantage in their environment. In addition, this research program will provide tools to investigate membrane proteins and their interactions, providing an ideal and unique training environment for my 3 undergraduates, 6 graduate students and 2 postdoctoral fellows, 3 of whom will be involved in conducting the microbiology, biochemistry and biophysical methods outline in aims 1 and 2. In keeping with my successful training of highly qualified personnel to date, my trainees will have the opportunity to contribute to high-impact publications and will gain broad expertise in membrane protein structural biology, microbiology, and biochemistry, preparing them for careers in basic scientific research and biotechnology.**

细菌依赖于从宿主获取多种营养物质来成功生长、定植或发病。共生菌和/或病原菌与宿主细胞竞争从金属到维生素的底物。由于这种竞争会影响感染的结果，病原体已经发展出多种营养吸收机制来提高它们的竞争力，从而提高它们定植和有效感染宿主的能力。我的研究项目的长期目标是通过分离膜蛋白并使用 X 射线晶体学和其他生物物理工具（例如微尺度热泳和生物层干涉测量法、表面等离子体共振和等温滴定量热法）进行原子分辨率结构和功能表征来阐明细菌营养吸收的分子基础。***我的 NSERC 研究 重点研究通过结合蛋白依赖性转运蛋白（BPDT）的营养吸收机制，该转运蛋白靶向金属离子、氨基酸和糖等多种配体，并被认为是许多细菌感染的毒力决定因素。我在本提案中概述的短期目标是破译 AfuABC 的机制，我们确定 AfuABC 是一种结合蛋白依赖性转运蛋白，负责主动摄取磷酸化碳水化合物。我们的结构见解将提供宿主营养物清除的分子基础，以及这些细菌如何在复杂环境中竞争营养物。***目标 1. 表征已识别的 AfuABC 同源物和旁系同源物的底物特异性和转运。***目标 2. 使用晶体结构、生长测定和生物分子相互作用剖析 AfuABC 转运磷糖的机制，以探测相互作用。 摄取系统的 AfuA 和 AfuBC 组件之间。 ***目标 3. 确定转运蛋白在发病机制中的作用以及这些细菌获得的底物的来源。***这些目标将导致对细菌病原体获取磷糖营养物以及该过程如何在其环境中提供竞争优势的批判性理解。此外，该研究项目将提供研究膜蛋白及其相互作用的工具，为我的 3 名本科生、6 名研究生和 2 名博士后研究员提供理想且独特的培训环境，其中 3 名将参与目标 1 和 2 中微生物学、生物化学和生物物理方法大纲的实施。根据我迄今为止对高素质人才的成功培训，我的学员将有机会为 高影响力的出版物，并将获得膜蛋白结构生物学、微生物学和生物化学方面的广泛专业知识，为基础科学研究和生物技术的职业生涯做好准备。 **