MEDIC - MicroED Imaging Center at UCLA

MEDIC -加州大学洛杉矶分校MicroED成像中心 项目摘要 我们建议在加州大学洛杉矶分校建立一个国家资源，用于开发、培训和传播 先进的电子衍射技术。冷冻电子显微镜（cryoEM）方法为 高通量大分子结构测定。CryoEM克服了X射线的基本障碍 大分子复合物的衍射测定：生长X射线级晶体。好在 微晶电子衍射（MicroED）的出现促进了新蛋白质结构的测定 以原子分辨率从微小的晶体中分离出来。MicroED利用电子之间的强相互作用 和纳米尺度的三维晶体，并利用新兴的冷冻EM仪器耦合 已经建立的晶体学方法。我们开创了MicroED，以实现里程碑式的发现，即我们 从小于波长的晶体中以原子分辨率确定了以前未知的蛋白质结构 可见光。这些技术进步，再加上先进的冷冻电镜的更大可用性， 仪器，为进一步改进高通量结构测定提供了机会。的 开发新的和更有效的方法来确定结构的MicroED开辟了新的途径 用于全面探索复杂的大分子结构，这些结构仍然是标准无法达到的 方法.这些系统包括大分子复合物，它们生长出小的、脆弱的或不完美的晶体。我们 提出的创新技术发展的MicroED是在四个类别：（1）改进的样品 筛选和制备，（2）新的精制和定相方法，（2）证明 MicroED用于天然产物和小分子，以及（4）设计用于研究结构的新硬件 真实的动态。与这些类型的组件相关的生物医学问题是广泛和影响的 生物医学，通过对疾病的基本理解和通过启用新的治疗平台。 我们的核心人员团队汇集了来自冷冻EM，晶体学， 生物化学，分子生物学和计算，以帮助开发下一代MicroED工具。这 这项工作将由全国各地的专家小组领导的项目提供信息，这些项目构成 重大的结构性挑战。总之，我们提出了一个资源，可以使nanocrystallography和 非专家的MicroED常规方法。广泛的用户培训和社区参与将进一步 传播MicroED技术，并将新的结构带到光中。

MEDIC – MicroED Imaging Center at UCLA Project Summary We are proposing to establish a national resource at UCLA for the development, training and dissemination of advanced electron diffraction technologies. Cryo-electron microscopy (cryoEM) methods promise new life to high-throughput macromolecular structure determination. CryoEM overcomes the fundamental barrier to X-ray diffraction determination of macromolecular complexes: growing X-ray grade crystals. Fortunately, the emergence of microcrystal electron diffraction (MicroED) facilitates the determination of new protein structures at atomic resolution from vanishingly small crystals. MicroED exploits the strong interaction between electrons and nano-scale three-dimensional crystals and takes advantage of emerging cryoEM instrumentation coupled to established crystallographic methods. We pioneered MicroED to achieve milestone discoveries, namely we determined previously unknown protein structures at atomic resolution from crystals smaller than the wavelength of visible light. These technological advances, coupled with the greater availability of advanced cryoEM instruments, present an opportunity for further improvement of high-throughput structure determination. The development of new and more efficient approaches to structure determination by MicroED opens new avenues for comprehensive exploration of complex macromolecular structures that remain out of reach for standard methods. These systems include macromolecular complexes that grow small, fragile, or imperfect crystals. Our proposed innovations to technology development in MicroED are in four categories: (1) improved sample screening and preparation, (2) novel refinement and phasing methods, (2) demonstrating the applicability of MicroED to natural products and small molecules, and (4) engineering new hardware for investigating structure dynamics in real time. The biomedical problems associated with these types of assemblies are broad and impact biomedicine, both through the basic understanding of disease and through enabling new therapeutic platforms. Our group of key personnel brings together expertise from all modalities of cryoEM, crystallography, biochemistry, molecular biology, and computation to help develop the next generation of MicroED tools. This effort will be informed by projects led by expert groups around the country working on projects that pose significant structural challenges. Together, we propose a resource that can make nanocrystallography and MicroED routine methodologies for non-experts. Extensive user training and community engagement will further disseminate the MicroED technology and bring new structures to light.