Fast, adaptive expectation-maximization alignment for Cryo-EM

Med Image Comput Comput Assist Interv. 2008;11(Pt 2):855-62. doi: 10.1007/978-3-540-85990-1_103.

Abstract

Cryo-EM is a method for reconstructing 3D structure of proteins without crystallization. The Expectation-Maximization (EM) algorithm is used in the alignment step of Cryo-EM reconstructions. The EM step is often a serious computational bottleneck for 3D reconstructions. This paper proposes a computationally adaptive version of the EM algorithm that speeds up the algorithm by a factor of 20 - 30. Experiments with noisy real-world data are included to show that the algorithm achieves this speedup without any significant loss of accuracy. Such speed ups are significant, allowing the reconstruction to converge in cpu-days rather than cpu-months.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Algorithms*
  • Cryoelectron Microscopy / methods*
  • Crystallography / methods*
  • Image Enhancement / methods*
  • Image Interpretation, Computer-Assisted / methods*
  • Proteins / ultrastructure*
  • Subtraction Technique*

Substances

  • Proteins