title: Direct methods in protein electron crystallography--beef liver catalase in its fully hydrated form at room temperature.
abstract: The crystal structure of beef liver catalase was determined ab initio in projection to 9 A resolution using electron diffraction data at room temperature from hydrated specimens maintained in an environmental chamber in the electron microscope. A conservative combination of symbolic addition with maximum entropy and likelihood led to a model with a Patterson correlation coefficient C = 0.89 to the observed data. This independent solution could then be compared favorably to a previous 23 A analysis of electron micrographs from frozen hydrated preparations. Prediction of the higher-resolution structure by extension of the lower-resolution image-based phase basis set also gave a good match to the direct-methods solution, particularly for the most intense reflections.
authors.affiliation: Electron Diffraction Department, Hauptman-Woodward Medical Research Institute, Inc., Buffalo, New York 14203-1196, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Dorset
authors.forename: C J
authors.initials: CJ
authors.lastname: Gilmore
mesh_terms: D000818:Animals; D002374:Catalase / Q000737:chemistry*; D002417:Cattle; D003460:Crystallization; D018360:Crystallography, X-Ray; D008099:Liver / Q000201:enzymology*; D008854:Microscopy, Electron; D013696:Temperature; D014867:Water
chemical_list: D014867:Water; D002374:Catalase