Exploration of parameters in cryo-EM leading to an improved density map of the E-coli ribosome
Exploration of parameters in cryo-EM leading to an improved density map of the E-coli ribosome
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DOI：
10.1016/j.jsb.2008.05.007
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发表时间：
2008-10-01
影响因子：
3
通讯作者：
Frank, Joachim
中科院分区：
文献类型：
--
作者：
LeBarron, Jamie;Grassucci, Robert A.;Frank, Joachim
在从冷冻EM数据集的核糖体复合物的3D重建中的许多图像处理参数被改变以测试它们对最终分辨率的影响。检查的参数是像素大小，窗口大小，和模式的傅立叶振幅增强在高空间频率。此外，在角度细化过程中，从大到小的像素大小的切换策略进行了探索。观察到分辨率（在傅立叶空间中）和粒子数量之间的关系遵循线性对数依赖性，这种关系似乎也适用于其他数据。通过优化上述参数，并使用线性对数外推到全数据集，估计半集的分辨率，我们获得了6.7埃分辨率（FSC = 0.5）的131，599个核糖体颗粒的3D图谱。(c)2008年爱思唯尔公司All rights reserved.
A number of image processing parameters in the 3D reconstruction of a ribosome complex from a cryo-EM data set were varied to test their effects on the final resolution. The parameters examined were pixel size, window size, and mode of Fourier amplitude enhancement at high spatial frequencies. In addition, the strategy of switching from large to small pixel size during angular refinement was explored. The relationship between resolution (in Fourier space) and the number of particles was observed to follow a lin-log dependence, a relationship that appears to hold for other data, as well. By optimizing the above parameters, and using a lin-log extrapolation to the full data set in the estimation of resolution from half-sets, we obtained a 3D map from 131,599 ribosome particles at 6.7 angstrom resolution (FSC = 0.5). (c) 2008 Elsevier Inc. All rights reserved.