ELECTRON MICROSCOPY OF MEMBRANE PROTEINS

膜蛋白的电子显微镜

• 批准号: 7124648
• 负责人: RONALD A MILLIGAN
• 金额: $ 32.32万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-23 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7124648
• 关键词: NIH Roadmap Initiative tag; antibiotics; bioimaging /biomedical imaging; cryoelectron microscopy; drug resistance; membrane transport proteins; molecular /cellular imaging; protein structure function; structural biology; three dimensional imaging /topography

DESCRIPTION (provided by applicant): Membrane proteins account for approximately 25% of gene products in organisms. They populate cell and organelle membranes and are essential for communication across these hydrophobic compartmental boundaries. They participate in recognition, transport and transduction processes that are fundamental attributes of living systems. In the work described here, the structure and mechanism of action of a number of membrane protein transporters will be investigated by cryo-electron microscopy and image analysis. Transporters from the ATP Binding Cassette (ABC), Major Facilitator (MFS) and Multi Antimicrobial Toxin Extrusion (MATE) superfamilies will be studied, as these are the current focus of parallel x-ray crystallographic investigations by one of the investigators. Members of the ABC, MFS and MATE superfamilies are of great medical importance as they are responsible for antibiotic and chemotherapy resistance. Cryo-EM and image analysis will be used to calculate 3D maps from (i) helical tubes and 2D crystals of MsbA - an ABC transporter - in various nucleotide-bound and substrate-bound states and, (ii) 2D crystals of FucP - an MFS transporter - with substrate bound. The maps will reveal the structures and provide insights into the transport mechanisms of representative members of these two membrane protein superfamilies. Additional experiments will focus on screening crystallization conditions to improve the order of the existing helical and 2D arrays, and to grow ordered arrays of other membrane proteins for EM structural studies.

描述（由申请人提供）：膜蛋白约占生物体中基因产物的25％。它们填充了细胞和细胞器膜，对于在这些疏水隔室边界之间进行通信至关重要。他们参与了生活系统基本属性的认可，运输和转导过程。 在此处描述的工作中，将通过冷冻电子显微镜和图像分析研究许多膜蛋白转运蛋白的作用的结构和机理。其中一项研究人员将研究来自ATP结合盒（ABC），主要促进因（MFS）和多抗菌毒素挤出（MAT）超家族的转运蛋白，因为其中一项研究人员是当前的X射线晶体学研究的焦点。 ABC，MFS和伴侣超家族的成员非常重要，因为它们负责抗生素和化学疗法耐药性。 冷冻EM和图像分析将用于计算来自（i）MSBA的（I）螺旋管和2D晶体的3D图 - ABC转运蛋白 - 在各种核苷酸结合和基板结合的状态中，以及（II）FUCP的2D晶体-MFS -MFS Transporter -tansporter -tansporter -tangorter -tomporter-与底物边界。这些地图将揭示结构并提供有关这两个膜蛋白超家族代表性成员的转运机制的见解。 其他实验将集中于筛选结晶条件，以改善现有的螺旋和2D阵列的顺序，并增加其他膜蛋白的有序阵列进行EM结构研究。