Identifying the Molecular Determinants of Ferredoxin Transport into the Periplasm of Pectobacterium spp.

确定铁氧还蛋白转运至果杆菌属周质的分子决定因素。

• 批准号: 2446840
• 金额: --
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2446840
• 关键词: Identifying; Molecular; Determinants; Ferredoxin; Transport

The uptake of Fe3+ is vital for the growth and survival of most bacteria. However, due to the poor water solubility of Fe3+, its concentration is low in the extracellular medium under physiological conditions, consequently passive diffusion is impractical for iron uptake by bacteria. To overcome this, Gram-negative bacteria capture iron from iron-containing substrates and host proteins. This is achieved through sophisticated active transport mechanisms. The Ferredoxin Uptake System (Fus) from the plant pathogen, Pectobacterium targets host ferredoxin (a small iron-sulphur cluster containing protein), binding it at the bacterial cell surface and transporting it through the outer-membrane transport protein FusA into the periplasm. Three proteins of the Fus system involved in uptake and processing of ferredoxin have been identified; FusA and FusB which mediate uptake, FusC which has been shown to process ferredoxin in the periplasm. This project is concerned with ferredoxin uptake, and is therefore focussed on FusA and FusB. Structural and biophysical data have provided insight into the Fus proteins involved, however, there remain some important questions, which this project will address, suing computational methods. The characterisation process has been broken down into focused objectives:1. Establish any alternative FusA-ferredoxin configurations to that proposed by x-ray structure2. Identify the role of the FusA plug domain in interactions with ferredoxin3. Characterise the passage of ferredoxin through FusA, establishing the extent of unfolding in ferredoxin in translocation4. Generate a model for FusB, exploring the possibility of it playing a role in removing the plug domain from FusA

Fe3+ 的吸收对于大多数细菌的生长和生存至关重要。然而，由于Fe3+的水溶性较差，生理条件下其在细胞外介质中的浓度较低，因此被动扩散对于细菌吸收铁是不切实际的。为了克服这个问题，革兰氏阴性细菌从含铁底物和宿主蛋白质中捕获铁。这是通过复杂的主动运输机制实现的。来自植物病原体果杆菌的铁氧还蛋白摄取系统 (Fus) 以宿主铁氧还蛋白（一种含有铁硫簇的蛋白质）为目标，将其结合在细菌细胞表面，并通过外膜转运蛋白 FusA 将其转运到周质中。已鉴定出参与铁氧还蛋白摄取和加工的 Fus 系统的三种蛋白质； FusA 和 FusB 介导摄取，FusC 已被证明可以在周质中处理铁氧还蛋白。该项目涉及铁氧还蛋白的吸收，因此重点关注 FusA 和 FusB。结构和生物物理数据提供了对所涉及的 Fus 蛋白的深入了解，但是，仍然存在一些重要问题，该项目将通过计算方法来解决这些问题。表征过程已分为几个重点目标：1．建立 X 射线结构2 提出的任何替代 FusA-铁氧还蛋白构型。确定 FusA 插头结构域在与 ferredoxin3 相互作用中的作用。表征铁氧还蛋白通过 FusA 的通道，确定铁氧还蛋白在易位中的解折叠程度4。为FusB生成模型，探讨其在从FusA中去除插头域中发挥作用的可能性