PUTATIVE OUTER MEMBRANE IRON/SIDEROPHORE RECEPTOR (YIUR)

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 概述 我们目前正在努力获得几个外膜蛋白的晶体结构从鼠疫耶尔森氏菌。 这些结构将深入了解细菌铁转运机制，并可能为鼠疫疫苗和诊断工具的开发提供信息。 膜蛋白的结构研究在包括表达、纯化、结晶和衍射的过程的所有阶段通常具有固有的问题。然而，为了最大限度地提高这项研究的成功率，我们正在同时研究几个目标。 到目前为止，我们已经成功地表达，纯化和结晶三个不同的蛋白，两个共享低同源性和一个非同源蛋白。此外，布坎南实验室已经有一个非常好的历史，成功地解决膜蛋白质结构。我们现在正处于项目的阶段，我们需要筛选大量的晶体以获得良好的衍射。与所有膜蛋白晶体一样，可能存在较低的有用衍射晶体比，但在上面，结构的影响将大于大多数可溶性蛋白。预计该项目将大大受益于高通量衍射筛选方法（自动计数器），以识别罕见的衍射晶体。 YiuR 铁是细菌生长和代谢所需的许多酶的重要组成部分。在生理pH的有氧环境中，铁主要以氧化的三价铁Fe（III）形式存在，其形成不溶性氢氧化物。为了在这些条件下获得铁，革兰氏阴性细菌如鼠疫杆菌通常会产生和释放高亲和力的三价铁结合化合物（称为铁载体），从环境中捕获铁。该表格中描述的蛋白质靶点是一种假定的外膜铁/铁载体受体，可能负责将铁转运到周质中。YiuR是一种tonB型受体蛋白，预测由跨膜的22链β桶和阻塞桶孔的塞结构域组成。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Overview We are currently working on obtaining the crystal structure of several outer membrane proteins from Y.pestis. The structures will give insights into bacterial iron transport mechanisms as well as potentially yield information for the development of a plague vaccine and diagnostic tools. Structural studies of membrane proteins often have inherent problems at all stages of the process including expression, purification, crystallisation and diffraction. However to maximise the success of this study we are working on several targets in parallel. So far, we have successfully expressed, purified and crystallised three distinct proteins two sharing low homology and one non-homologous protein. Additionally the Buchanan laboratory already has a very good history of successfully solving membrane protein structures. We are now at the stage of the project where we need to screen a lot of crystals for good diffraction. As with all membrane protein crystals there might be a lower useful diffraction to crystal ratio but on th upside the impact of the structure(s) will be greater than for most soluble proteins. It is expected that this project will greatly benefit from high throughput diffraction screening methods (automounter) to identify rare well difracting crystals. YiuR Iron is an essential component of many enzymes required for growth and metabolism of bacteria In aerobic environments at physiological pH, iron exists predominantly as oxidized ferric iron, Fe(III), which forms insoluble hydroxides. In order to acquire iron under these conditions, gram-negative bacteria like Y.pestis usually produce and release high-affinity ferric iron-binding compounds (called siderophores), which capture iron from the environment. The protein target described on this form is a putative outer membrane iron/siderophore receptor and could be responsible for the transport of iron into the periplasm. YiuR is a tonB type receptor protein predicted to consist of a 22 stranded Beta barrel spanning the membrane and a plug domain blocking the pore of the barrel.