VISUALIZATION SOFTWARE FOR ELECTRON MICROSCOPY

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。列出的机构是 中心，不一定是研究者的机构。 我们正在开发交互式分析三维的软件 通过电子显微镜（EM）获得的密度图。 分析目的 来确定分子机器的结构和内部工作方式， 如病毒、核糖体、微管和马达、肌丝， 几十个其他的系统是目前研究的目标。 是 认为生物体中的大多数蛋白质都是 分子组装 过去实验方法的进展 几年来大大加快了对这些系统的研究。 的 电磁密度图的主要数据库 (http：//www.ebi.ac.uk/msd-srv/emsearch/index.html）成立于2002年 现在（2010年）有773个条目。 用于推导结构的软件 许多实验室正在积极开发这些地图。 我们的软件显示密度图的轮廓表面。 地图从 电子显微镜的分辨率在5 - 100埃范围内 这太粗糙了，无法看到原子细节。 分析涉及拟合 已知的原子结构从晶体学到地图上， 识别对应于未识别蛋白质的图谱中的结构， 并对同一系统在不同实验条件下的图谱进行了比较 推断配体的构象变化或结合的条件， 特定的大分子。 我们的软件工具是 UCSF Chimera分子建模包，支持拟合，雕刻 密度区域、着色地图以及在地图中构建粗糙模型。 在过去，我们添加了沿沿着 显示密度值的任意方向和可移动的平面 切割表面。

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. We are developing software for interactively analyzing 3-dimensional density maps obtained by electron microscopy (EM). The analysis aims to determine structures and inner workings of molecular machines such as viruses, ribosomes, microtubules and motors, muscle filaments, and dozens of others systems that are targets of current research. It is believed that most proteins in living organisms are parts of large molecular assemblies. Advances in experimental methods in the past several years have greatly accelerated research on these systems. The primary database of EM density maps (http://www.ebi.ac.uk/msd-srv/emsearch/index.html) was founded in 2002 and now (2010) has 773 entries. Software for deducing structures from these maps is being actively developed by many labs. Our software displays contour surfaces of density maps. Maps from electron microscopy have resolutions in the 5 - 100 Angstrom range which is too coarse to see atomic detail. Analysis involves fitting known atomic structures from crystallography into the maps, identifying structures in maps corresponding to unidentified proteins, and comparing maps of the same system under different experimental conditions to deduce conformational changes or binding of ligands or specific macromolecules. Our software tools, which are part of the UCSF Chimera molecular modeling package, support fitting, carving out density regions, coloring maps, and building coarse models in maps. In the past we have added the ability to slice maps along an arbitrarily oriented and movable plane displaying density values on the cut surface.