title: Crystallization of diphtheria toxin.
abstract: Two new crystal forms (forms III and IV) have been grown of diphtheria toxin (DT), which kills susceptible cells by catalyzing the ADP-ribosylation of elongation factor 2, thereby stopping protein synthesis. Forms III and IV diffract to 2.3 A and 2.7 A resolution, respectively. Both forms belong to space group C2; the unit cell parameters for form III are a = 107.3 A, b = 91.7 A, c = 66.3 A and beta = 94.7 degrees and those for form IV are a = 108.3 A, b = 92.3 A, c = 66.1 A and beta = 90.4 degrees. Both forms have one protein chain per asymmetric unit with the dimeric molecule on a twofold axis of symmetry. Form IV is exceptional among all crystal forms of DT in that it can be grown reproducibly. Thus the form IV crystals should yield a crystallographic structure giving insight into the catalytic, receptor-binding and membrane-insertion properties of DT.
authors.affiliation: Molecular Biology Institute, University of California, Los Angeles 90024.
authors.forename: G
authors.initials: G
authors.lastname: Fujii
authors.forename: S H
authors.initials: SH
authors.lastname: Choe
authors.forename: M J
authors.initials: MJ
authors.lastname: Bennett
authors.forename: D
authors.initials: D
authors.lastname: Eisenberg
mesh_terms: D003460:Crystallization; D004167:Diphtheria Toxin / Q000737:chemistry* / Q000302:isolation & purification; D007202:Indicators and Reagents; D011487:Protein Conformation; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D004167:Diphtheria Toxin; D007202:Indicators and Reagents