A fast iterative convolution weighting approach for gridding-based direct Fourier three-dimensional reconstruction with correction for the contrast transfer function

作者：Abrishami V; Bilbao Castro J R; Vargas J; Marabini R; Carazo J M; Sorzano C O S^*

来源：Ultramicroscopy, 2015, 157: 79-87.

DOI：10.1016/j.ultramic.2015.05.018

• Cryo-electron microscopy
• Three-dimensional reconstruction
• CTF correction
• Single Particle Analysis

We describe a fast and accurate method for the reconstruction of macromolecular complexes from a set of projections. Direct Fourier inversion (in which the Fourier Slice Theorem plays a central role) is a solution for dealing with this inverse problem. Unfortunately, the set of projections provides a non-equidistantly sampled version of the macromolecule Fourier transform in the single particle held (and, therefore, a direct Fourier inversion) may not be an optimal solution. In this paper, we introduce a griddling-based direct Fourier method for the three-dimensional reconstruction approach that uses a weighting technique to compute a uniform sampled Fourier transform. Moreover, the contrast transfer function of the microscope, which is a limiting factor in pursuing a high resolution reconstruction, is corrected by the algorithm. Parallelization of this algorithm, both on threads and on multiple CPU's, makes the process of three-dimensional reconstruction even faster. The experimental results show that our proposed gridding-based direct Fourier reconstruction is slightly more accurate than similar existing methods and presents a lower computational complexity both in terms of time and memory, thereby allowing its use on larger volumes. The algorithm is fully implemented in the open-source Xmipp package and is downloadable from http://xmipp.cnb.csic.es.

• 出版日期2015-10