Combining electron microscopic with X-ray crystallographic structures
Combining electron microscopic with X-ray crystallographic structures
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DOI：
10.1006/jsbi.2002.4435
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发表时间：
2001-12-01
影响因子：
3
通讯作者：
Pletnev, SV
中科院分区：
文献类型：
--
作者：
Rossmann, MG;Bernal, R;Pletnev, SV
已经开发了一种算法，用于将三维原子结构放置到适当比例的低温电子显微镜图中。该过程的第一阶段是进行三维角度搜索，其中x射线晶体学确定的结构的重心放置在低温电子显微镜图中的选定位置上。配合的质量是通过每个原子位置的密度之和来衡量的。第二阶段是细化三个角度和三个最佳（通常是25到100）的平移参数。这种改进的有用标准包括原子位置的密度总和，负或低密度原子的缺乏，原子结构的对称相关位置之间不存在原子冲突，以及地图中可识别特征与其在拟合原子结构上的位置之间的距离。这些改进通常会导致最初选择的收敛，最高得分适合少数（大约3到8）可接受的可能性。通常情况下，最好的剩余匹配明显优于其他任何一个。(C) 2002 Elsevier Science （USA）。
An algorithm has been developed for placing three-dimensional atomic structures into appropriately scaled cryoelectron microscopy maps. The first stage in this process is to conduct a three-dimensional angular search in which the center of gravity of an X-ray crystallographically determined structure is placed on a selected position in the cryoelectron microscopy map. The quality of the fit is measured by the sum of the density at each atomic position. The second stage is to refine the three angles and three translational parameters for the best (usually 25 to 100) fits. Useful criteria for this refinement include the sum of densities at atomic sites, the lack of atoms in negative or low density, the absence of atomic clashes between symmetry-related positions of the atomic structure, and the distances between identifiable features in the map and their positions on the fitted atomic structure. These refinements generally lead to a convergence of the originally chosen, top scoring fits to just a few (about 3 to 8) acceptable possibilities. Usually, the best remaining fit is clearly superior to any of the others. (C) 2002 Elsevier Science (USA).