We address recovery of the three-dimensional backbone structure of single polypeptide proteins from single-particle cryo-electron microscopy (Cryo-SPA) data. Cryo-SPA produces noisy tomographic projections of electrostatic potentials of macromolecules. From these projections, we use methods from shape analysis to recover the three-dimensional backbone structure. Thus, we view the reconstruction problem as an indirect matching problem, where a point cloud representation of the protein backbone is deformed to match 2D tomography data. The deformations are obtained via the action of a matrix Lie group. By selecting a deformation energy, the optimality conditions are obtained, which lead to computational algorithms for optimal deformations. We showcase our approach on synthetic data, for which we recover the three-dimensional structure of the backbone.
@article{arxiv.2410.00833,
title = {Geometric shape matching for recovering protein conformations from single-particle Cryo-EM data},
author = {Erik Jansson and Jonathan Krook and Klas Modin and Ozan Öktem},
journal= {arXiv preprint arXiv:2410.00833},
year = {2024}
}