title: A strategy for electron tomographic data collection and crystallographic reconstruction of biological bundles.
abstract: Structures of highly ordered biological bundles have unique features which call for special experimental and computational methods in electron cryomicroscopy. They can be considered as three-dimensional quasi-crystals and reconstructed using a crystallographic approach. However, they are neither "infinitely" large with respect to the borders of the bundle, nor are they a single unit cell in thickness along the viewing direction. Also, because of their shape, bundles do not generally have a preferred azimuthal orientation, which poses challenges for orientation estimation and refinement. We developed a strategy for recording and processing electron cryomicroscopic images that differs from classical two-dimensional crystalline reconstruction techniques. These developments allowed us to merge data from tomographic tilt series of ice-embedded acrosomal bundles. The goal is to determine accurately amplitudes and phases at the diffraction maxima in terms of hkl indices, and compute a three-dimensional map from the diffraction data.
authors.affiliation: National Center for Macromolecular Imaging, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: M B
authors.initials: MB
authors.lastname: Sherman
authors.forename: J
authors.initials: J
authors.lastname: Jakana
authors.forename: S
authors.initials: S
authors.lastname: Sun
authors.forename: P
authors.initials: P
authors.lastname: Matsudaira
authors.forename: W
authors.initials: W
authors.lastname: Chiu
authors.forename: M F
authors.initials: MF
authors.lastname: Schmid
mesh_terms: D000177:Acrosome / Q000648:ultrastructure*; D000818:Animals; D018360:Crystallography, X-Ray / Q000379:methods; D005615:Freezing; D006737:Horseshoe Crabs; D007091:Image Processing, Computer-Assisted; D008297:Male; D008854:Microscopy, Electron / Q000379:methods*; D008961:Models, Structural; D013094:Spermatozoa / Q000648:ultrastructure*; D014054:Tomography