Center for Structure of Membrane Proteins

整合膜蛋白占蛋白质组的约30%，在代谢， 调节和细胞间过程。人类MP是约40%的所有治疗药物的靶标，但是 MP结构的数目小于可溶性蛋白质结构数目的0.5%。拟议的中心 汇集了美国五个机构的11名研究人员，共同致力于实现以下总体目标： 确定高生物医学影响的整体MP结构。 具体目标平衡了多个优先事项。目标1-3是广泛的，寻求获得结构， 提供了来自（1）E.大肠杆菌，（2）极端微生物，和（3）人类。广泛的目标基础被分流 通过动态生物信息学筛选，在第一年年底前直接关注最易处理的集合。目标4和 5个是密集型的，针对具有最高生物医学相关性和影响力的家庭， 目的4涉及特定的原核MP;目的5涉及大多数的 具有挑战性的真核MP，包括人类治疗靶点和核孔组分 复杂.目标6通过专门为MP开发的比较建模来利用MP结构。 十大核心能力实现了支持目标的方法，涵盖了结构的各个方面 测定，包括靶点选择、克隆、表达、纯化、结晶、结构 通过X射线晶体学、NMR光谱学或电子显微镜测定，以及建模。核 提供多点进入高吞吐量启用结构生物学伙伴关系。表达核心 涵盖原核和真核（包括HEK）体内系统，一个使用绿色绿色荧光 蛋白表达检测，以及E.基于大肠杆菌的无细胞体外系统优化MP表达。 蛋白质纯化核心，在几种表征方法的帮助下，提供了纯的均匀的， 不含过量洗涤剂的稳定蛋白质。电子显微镜核心提供了进一步的表征， 二维结晶。结构测定方法包括X射线衍射和NMR光谱，其中 无细胞表达已被利用于快速测定细胞内蛋白质的组合标记策略。 骨干结构。X射线晶体学核心提供机器人晶体试验和衍射， 先进的光源光束线8.3.1，世界上最具生产力的蛋白质晶体学设施之一。 总的来说，主要研究者的综合专业知识为实现这一目标提供了一个独特的环境。 提出的目标。

Integral membrane proteins account for ~30% of a proteome and play critical roles in metabolic, regulatory and intercellular processes. Human MPs are the targets for ~40% of all therapeutic drugs, but the number of MP structures is less than 0.5% ofthe number of soluble protein structures. The proposed Center brings together 11 Investigators at five US institutions to focus cooperatively on the overarching aim of determining integral MP structures of high biomedical impact. The Specific Aims balance multiple priorities. Aims 1-3 are extensive, seeking to obtain structures by providing many targets from (1) E. coli, (2) extremophiles, and (3) human. The broad target base is triaged by dynamic bioinformatic screening to direct focus on the most tractable set by the end of year 1. Aims 4 and 5 are intensive, targeting families of highest biomedical relevance and impact for which structures have generally not yet been obtained; Aim 4 concerns specific prokaryotic MPs; Aim 5 involves the most challenging eukaryotic MPs, including human therapeutic targets and components of the nuclear pore complex. Aim 6 leverages MP structures by comparative modeling developed specifically for MPs. Ten core capabilities implement the methods that support the aims and cover every aspect of structure determination, including target selection, cloning, expression, purification, crystallization, structure determination by X-ray crystallography, NMR spectroscopy or electron microscopy, and modeling. The cores provide multi-point entry to High-Throughput-Enabled Structural Biology Partnerships. Expression cores cover prokaryotic and eukaryotic (including HEKs) in vivo systems, one using green green fluorescent protein detection of expression, and an E. coli based cell-free in vitro system optimized for MP expression. The protein purification core, aided by several characterization methods, provides pure homogeneous and stable proteins free of excess detergent. The electron microscopy core provides fijrther characterization and 2D crystallization. Structure determination methods include X-ray diffraction and NMR spectroscopy, where cell-free expression has been harnessed to a combinatorial labeling strategy for rapid determination of backbone structures. The X-ray crystallography core provides robotic crystal trials and diffraction at the Advanced Light Source beamline 8.3.1, one ofthe world's most productive protein crystallography facilities. Overall, the combined expertise of principal investigators provides a unique environment to achieve the proposed aims.