title: A multiresolution approach to orientation assignment in 3D electron microscopy of single particles.
abstract: Three-dimensional (3D) electron microscopy (3DEM) aims at the determination of the spatial distribution of the Coulomb potential of macromolecular complexes. The 3D reconstruction of a macromolecule using single-particle techniques involves thousands of 2D projections. One of the key parameters required to perform such a 3D reconstruction is the orientation of each projection image as well as its in-plane orientation. This information is unknown experimentally and must be determined using image-processing techniques. We propose the use of wavelets to match the experimental projections with those obtained from a reference 3D model. The wavelet decomposition of the projection images provides a framework for a multiscale matching algorithm in which speed and robustness to noise are gained. Furthermore, this multiresolution approach is combined with a novel orientation selection strategy. Results obtained from computer simulations as well as experimental data encourage the use of this approach.
authors.affiliation: Escuela Politécnica Superior, Universidad San Pablo-CEU, Campus Urb., Madrid, Spain. coss@cnb.uam.es
authors.forename: C O S
authors.initials: CO
authors.lastname: Sorzano
authors.forename: S
authors.initials: S
authors.lastname: Jonić
authors.forename: C
authors.initials: C
authors.lastname: El-Bez
authors.forename: J M
authors.initials: JM
authors.lastname: Carazo
authors.forename: S
authors.initials: S
authors.lastname: De Carlo
authors.forename: P
authors.initials: P
authors.lastname: Thévenaz
authors.forename: M
authors.initials: M
authors.lastname: Unser
mesh_terms: D000465:Algorithms; D001436:Bacteriorhodopsins / Q000737:chemistry; D018834:Chaperonin 60 / Q000737:chemistry; D003198:Computer Simulation; D021621:Imaging, Three-Dimensional / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry*; D008854:Microscopy, Electron / Q000379:methods*; D008958:Models, Molecular; D010316:Particle Size
chemical_list: D018834:Chaperonin 60; D046911:Macromolecular Substances; D001436:Bacteriorhodopsins