Specialized Macromolecular Crystallography

项目概要/摘要-核心3 -专业高分子晶体学 该技术运营核心将提供九项急需的先进技术， 结构生物学用户社区的成员致力于解决特别具有挑战性的问题。它们是：1） 当一个晶体不够时，多晶体策略，2）当准备时，天然元素定相 衍生物是不切实际的，3）当晶体太脆而不能处理时，来自托盘的原位衍射， 非低温下的衍射，用于功能研究或当低温保护使衍射 更糟糕的是，5）用于在从偏振到偏振的循环中找到晶体的替代可视化技术 显微镜到在线X射线断层扫描（CBOXAR）和光栅网格搜索的小X射线束在 6）基于第一-第二衍射面的数据质量预测; 原理和尺度衍射模拟技术，以推导出最佳的数据采集参数 基于关于给定样本的所有可用信息，7）可用波束的综合阵列 性能，包括我们即将完成的微焦点GEMINI光束线8）自动光学重新定心 技术（AUORA），使实验能够自主迁移到任何ALS光束线，以优化 束线利用9）明确的“目标文件格式”规范，以便在必要时可以进行实验 迁移到ALS之外，例如X射线自由电子激光器。 所有这些技术都将通过ALS-ENABLE网站联系在一起，该网站不仅跟踪样本， 和数据处理结果，但它们之间的相互兼容关系。这将是必不可少的， 管理必须探索的数据集的组合爆炸，以尽可能最好地缝合在一起 一个完整的数据集为一个给定的项目。这种平均将是本机元件定相的关键，其中信号 从任何单一的样品很少是足够好的相位。该网站还将作为一个知识库， 能够根据用户目前拥有的所有数据和预测， 由我们独特的精确衍射模拟技术提供。例如，将建议 如果SAXS（TOC 2）表明他们的分子是内在有序的，但衍射是 分辨率为6 μ m。如果原位衍射也很差，则建议寻找新的 使用X射线足迹法（ALS-ENABLE外）或cryo-EM（ALS外）确定晶体形式。 我们希望这一资源将吸引广泛的区域和国家地理分布的用户。通过 解决衍射差的问题，需要在多个温度下进行功能研究，需要 对于原生元素定相，通过分散晶体中心问题，我们将利用多样性 将ALS光束线转换为一个连贯且易于获取的资源。

Project Summary/Abstract - Core 3 – Specialized Macromolecular Crystallography This Technology Operations Core will serve up nine advanced technologies that are seriously needed by members of the structural biology user community working on particularly challenging problems. These are: 1) multi-crystal strategy for when one crystal is not enough, 2) native element phasing for when preparing derivatives is impractical, 3) in-situ diffraction from trays for when the crystals are too fragile to handle, 4) diffraction at non-cryogenic temperatures, for functional studies or when cryo-protection makes diffraction worse, 5) alternative visualization technologies for finding crystals in loops ranging from polarization microscopy to online X-ray tomography (CBOXAR) and raster grid searches of a small x-ray beam over the face of the sample to probe for diffraction quality exhaustively, 6) data quality prediction based on first- principles and at-scale diffraction simulation technology to deduce the best possible data collection parameters based on all available information about a given sample, 7) a comprehensive array of available beam properties, including our soon-to-be-completed micro-focus GEMINI beamline 8) automatic optical re-centering technology (AUORA) to enable autonomous migration of experiments to any ALS beamline, for optimizing beamline utilization 9) a clear “targeting file format” specification so that, if necessary, experiments can be migrated outside the ALS, such as to X-ray Free Electron Lasers. All these technologies will be tied together by the ALS-ENABLE website, which will track not just the samples and data processing results, but the inter-compatibility relationships between them. This will be essential for managing the combinatorial explosion of data sets that must be explored to stitch together the best possible complete data set for a given project. This averaging will be key to native-element phasing, where the signal from any single sample is seldom good enough for phasing. The website will also serve as a knowledge base, capable of making recommendations to Users based on all the data they currently have, and the predictions provided by our uniquely accurate diffraction simulation technology. For example, it will be recommended that they try in-situ diffraction if SAXS (TOC 2) shows that their molecule is intrinsically ordered but diffraction is stuck at 6 Å resolution. If in-situ diffraction is also poor, then the recommendation will be to search for a new crystal form using X-ray Footprinting (outside ALS-ENABLE) or cryo-EM (outside ALS). We expect this Resource will appeal to a wide regional and national geographic distribution of users. By addressing the problem of poor diffraction, the need for functional studies at multiple temperatures, the need for native element phasing, and by de-centralizing the crystal centering problem we will leverage the diversity of the ALS beamlines into a coherent and easily accessible Resource.