title: Dehydration leads to a phase transition in monoclinic factor XIII crystals.
abstract: Monoclinic factor XIII crystals have been transferred to a solution containing increasing amounts of the precipitant PEG 6000. At a concentration of about 36%(w/v) PEG 6000, a phase transition was observed. The space group of the crystals was preserved on the transition, but half of the 2(1) screw axes were lost, which meant that the unit-cell volume and the content of the asymmetric unit were doubled. The structure of factor XIII in the new crystal form was solved by molecular replacement. About 80% of the changes accompanying the transition can be explained by a rigid-body rotation of half of the factor XIII dimers in the lattice by about 5 degrees. The remaining changes are mostly small interdomain movements of the four domains which constitute one factor XIII monomer.
authors.affiliation: Institute of Molecular Biotechnology, Department of Structural Biology and Crystallography, D-07708 Jena, Germany. msweiss@imb-jena.de
authors.forename: M S
authors.initials: MS
authors.lastname: Weiss
authors.forename: R
authors.initials: R
authors.lastname: Hilgenfeld
mesh_terms: D003460:Crystallization; D018360:Crystallography, X-Ray; D019281:Dimerization; D005176:Factor XIII / Q000737:chemistry*; D006801:Humans; D011092:Polyethylene Glycols / Q000494:pharmacology; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D005176:Factor XIII