Methods for aligning and for averaging 3D volumes with missing data
Methods for aligning and for averaging 3D volumes with missing data
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DOI：
10.1016/j.jsb.2007.09.018
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发表时间：
2008-03-01
影响因子：
3
通讯作者：
Booth, Christopher R.
中科院分区：
文献类型：
--
作者：
Schmid, Michael F.;Booth, Christopher R.
包含多个离散粒子副本的层析成像重建的可见性和分辨率可以通过对校正后的子层析成像进行平均来增强。然而，电子断层扫描中的“缺失楔”很容易导致错误对准。我们探索了一种傅里叶空间相互关联方法，采用适当的加权方案来对齐和平均不同的体积数据集，每个数据集由于有限的试样倾斜而有不同的缺失数据。这种方法既不依赖于预先存在的模板，也不依赖于对丢失数据的几何形状、方向或数量的确切了解。本文介绍了一种通过对缺失数据的不同方向的体进行连续对齐和平均来逐渐“填充”缺失数据的方法。我们通过一组具有不同对称性和缺失数据程度的模拟数据验证了这些技术。我们还成功地将这些程序应用于实验低温电子层析数据[Chang， j.t., Schmid, m.f., Rixon, f.j., and Chin， W., 2007]。电子冷冻断层扫描显示疱疹病毒衣壳的入口。[j]中国生物医学工程学报，2011,31 (2):481 - 481；Schmid, m.f., Paredes, a.m., Khant, h.a., Soyer， F, Aldrich, h.c., Chiu， W, and Shively, j.m., 2006。新波利盐硫杆菌羧基体的低温电子断层扫描结构。[j].中国生物医学工程学报，2004,26(4):526-535。(C) 2007爱思唯尔公司版权所有。
The visibility and resolution of a tomographic reconstruction containing multiple copies of discrete particles can be enhanced by averaging subtomograms after they are corrected aligned. However, the "missing wedge" in electron tomography can easily lead to erroneous alignment. We have explored a Fourier space cross-correlation method with a proper weighting scheme to align and average different sets of volumetric data, each of which has different missing data due to the limited specimen tilts. This approach depends neither on a preexisting template, nor an exact knowledge of the geometry, orientation, or amount of the missing data. This paper introduces a procedure where the missing data might be gradually "filled in" by consecutively aligning and averaging volumes with different orientations of their missing data. We have validated these techniques by a set of simulated data with various symmetries and extent of missing data. We have also successfully applied these procedures to experimental cryo-electron tomographic data [Chang, J.T., Schmid, M.F., Rixon, F.J., and Chin, W., 2007. Electron cryotomography reveals the portal in the herpesvirus capsid. J. Virol. 81, 2065-2068; Schmid, M.F., Paredes, A.M., Khant, H.A., Soyer, F., Aldrich, H.C., Chiu, W., and Shively, J.M., 2006. Structure of Halothiobacillus neapolitanus carboxysomes by cryo-electron tomography. J. Mol. Biol. 364, 526-535]. (C) 2007 Elsevier Inc. All rights reserved.