title: Images of purple membrane at 2.8 A resolution obtained by cryo-electron microscopy.
abstract: Improvements in technique have produced electron micrographs of purple membrane that provide, after computer analysis, reproducibly measurable diffraction peaks extending to 2.8 A (1 A = 0.1 nm). The improvements include better specimen preparation, a more stable cryo-electron microscope with better alignment and the addition of an image-processing step, which gives weights to local areas of the image according to the local strength of the periodic component of the image. These improvements have enabled the calculation of a directly phased projection map at 2.8 A resolution.
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge, U.K.
authors.forename: J M
authors.initials: JM
authors.lastname: Baldwin
authors.forename: R
authors.initials: R
authors.lastname: Henderson
authors.forename: E
authors.initials: E
authors.lastname: Beckman
authors.forename: F
authors.initials: F
authors.lastname: Zemlin
mesh_terms: D001436:Bacteriorhodopsins / Q000032:analysis*; D005615:Freezing; D008854:Microscopy, Electron / Q000379:methods
chemical_list: D001436:Bacteriorhodopsins