title: Microcrystals of the annexin, p68: paracrystal to crystal transition and molecular packing as determined by electron microscopy and image reconstruction.
abstract: The calcium-sensitive, membrane-binding annexin, p68, has been crystallized from solutions of polyethylene glycol and ammonium sulfate. Our electron microscopy and X-ray diffraction data indicate that p68 crystals are tetragonal, in space group P4(1), and have unit cell dimensions of a = b = 68.4 A and c = 209.6 A. The mechanism of crystallization from polyethylene glycol involves a transition from a paracrystalline form to ordered crystals by lateral reordering of chains of molecules extended along the c axis. These chains are directional and might reflect a mechanism whereby the two different ends of (chains of) the p68 molecules interact with different membranes.
authors.affiliation: Department of Pharmacology, University of Virginia, Charlottesville 22901.
authors.forename: B L
authors.initials: BL
authors.lastname: Gabriel
authors.forename: K
authors.initials: K
authors.lastname: Taylor
authors.forename: C E
authors.initials: CE
authors.lastname: Creutz
authors.forename: R H
authors.initials: RH
authors.lastname: Kretsinger
mesh_terms: D000818:Animals; D017317:Annexin A6; D002135:Calcium-Binding Proteins / Q000737:chemistry* / Q000648:ultrastructure; D002417:Cattle; D003460:Crystallization; D007091:Image Processing, Computer-Assisted; D008854:Microscopy, Electron; D014961:X-Ray Diffraction
chemical_list: D017317:Annexin A6; D002135:Calcium-Binding Proteins