title: Physical detwinning of hemihedrally twinned hexagonal crystals of bacteriorhodopsin.
abstract: Hexagonal crystals of the membrane protein bacteriorhodopsin of space group P6 3 grown in lipidic cubic phase are twinned hemihedrally. It was shown that slow changes of salt concentration in the mother liquor lead to a split of crystals so that the split parts preserved high diffraction quality. Analysis of diffraction data from split crystals by Yeates statistic and Britton plot showed that the split parts are free of twinning. It is concluded that crystals of bacteriorhodopsin are composed of several macroscopic twinning domains with sizes comparable to the original crystal. The appearance of twinning domains during crystal growth and the mechanism of splitting are discussed.
authors.affiliation: Institute for Structural Biology (IBI-2), Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: Rouslan
authors.initials: R
authors.lastname: Efremov
authors.forename: Rouslan
authors.initials: R
authors.lastname: Moukhametzianov
authors.forename: Georg
authors.initials: G
authors.lastname: Büldt
authors.forename: Valentin
authors.initials: V
authors.lastname: Gordeliy
mesh_terms: D001436:Bacteriorhodopsins / Q000032:analysis / Q000737:chemistry* / Q000648:ultrastructure*; D001665:Binding Sites; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D003461:Crystallography / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D046912:Multiprotein Complexes / Q000737:chemistry / Q000648:ultrastructure; D011485:Protein Binding
chemical_list: D046912:Multiprotein Complexes; D001436:Bacteriorhodopsins