title: Spatially filtered images of B. subtilis alpha-amylase crystals.
abstract: Microcrystals of B. subtilis alpha-amylase have been negatively stained and examined by electron microscopy. The micrographs were then subjected to spatial filtering and averaging using a Fourier transform procedure programmed for a mini computer. From these 'enhanced' images refined crystallographic parameters were obtained and a model for the packing of the asymmetric units within the crystal was derived. In addition, these parameters obtained from electron microscopy are compared with those derived from limited X-ray diffraction data on macrocrystals of the same form.
mesh_terms: D000681:Amylases; D001412:Bacillus subtilis / Q000201:enzymology*; D055598:Chemical Phenomena; D002621:Chemistry; D003460:Crystallization; D005583:Fourier Analysis; D008854:Microscopy, Electron; D008905:Minicomputers; D000516:alpha-Amylases
chemical_list: D000681:Amylases; D000516:alpha-Amylases