title: Two-dimensional crystallization of human vitamin K-dependent gamma-glutamyl carboxylase.
abstract: Planar-tubular two-dimensional (2D) crystals of human vitamin K-dependent gamma-glutamyl carboxylase grow in the presence of dimyristoyl phosphatidylcholine (DMPC). Surprisingly, these crystals form below the phase transition temperature of DMPC and at the unusually low molar lipid-to-protein (LPR) ratio of 1, while 2D crystals are conventionally grown above the phase transition temperature of the reconstituting lipid and significantly higher LPRs. The crystals are up to 0.75 microm in the shorter dimension of the planar tubes and at least 1 microm in length. Due to the planar-tubular nature of the crystals, two lattices are present. These are rotated by nearly 90 degrees in respect to each other. The ordered arrays exhibit p12(1) plane group symmetry with unit cell dimensions of a=83.7 A, b=76.6 A, gamma=91 degrees. Projection maps calculated from images of negatively stained and electron cryo-microscopy samples reveal the human vitamin K-dependent gamma-glutamyl carboxylase to be a monomer.
authors.affiliation: Georgia Institute of Technology, School of Biology, 310 Ferst Drive, Atlanta, GA 30332-0230, USA. Ingeborg.Krey@biology.gatech.edu
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Schmidt-Krey
authors.forename: Winfried
authors.initials: W
authors.lastname: Haase
authors.forename: Vasantha
authors.initials: V
authors.lastname: Mutucumarana
authors.forename: Darrel W
authors.initials: DW
authors.lastname: Stafford
authors.forename: Werner
authors.initials: W
authors.lastname: Kühlbrandt
mesh_terms: D019735:Carbon-Carbon Ligases / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D006801:Humans; D008099:Liver / Q000201:enzymology; D020836:Protein Structure, Quaternary
chemical_list: D019735:Carbon-Carbon Ligases; C020660:glutamyl carboxylase