title: Crystallization and preliminary crystallographic analysis of Mycoplasma arthritidis-derived mitogen complexed with peptide/MHC class II antigen.
abstract: Mycoplasma arthritidis-derived mitogen (MAM), a bacterial superantigen, has been crystallized in complex with its human receptor, major histocompatibility complex (MHC) class II antigen, by the hanging-drop vapor-diffusion method. Crystals were obtained under three conditions, with ammonium sulfate, phosphate salt and PEG 8000 as the precipitant. The crystals grown under these conditions all belong to space group I222, with the same unit-cell parameters: a = 137.4, b = 178.2, c = 179.6 A. Diffraction data were collected to 3.3 and 3.4 A resolution from crystals of native and selenomethionylated MAM-MHC complexes, respectively. Self- and cross-rotation function calculations suggest the presence of two complex molecules in the asymmetric unit, resulting in a V(M) of 4.0 and a solvent content of 69%. An interpretable electron-density map was produced using a combination of molecular replacement and SAD phasing.
authors.affiliation: Wadsworth Center, New York State Department of Health, Empire State Plaza, PO Box 509, Albany, New York 12201-0509, USA.
authors.forename: Yiwei
authors.initials: Y
authors.lastname: Zhao
authors.forename: Zhong
authors.initials: Z
authors.lastname: Li
authors.forename: Sandra
authors.initials: S
authors.lastname: Drozd
authors.forename: Yi
authors.initials: Y
authors.lastname: Guo
authors.forename: Robert
authors.initials: R
authors.lastname: Stack
authors.forename: Charles
authors.initials: C
authors.lastname: Hauer
authors.forename: Hongmin
authors.initials: H
authors.lastname: Li
mesh_terms: D000941:Antigens; D000942:Antigens, Bacterial / Q000737:chemistry; D002845:Chromatography; D018360:Crystallography, X-Ray / Q000379:methods; D004058:Diffusion; D004583:Electrons; D004926:Escherichia coli / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008285:Major Histocompatibility Complex; D013058:Mass Spectrometry; D008934:Mitogens / Q000737:chemistry*; D045645:Mycoplasma arthritidis / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011506:Proteins; D011994:Recombinant Proteins / Q000737:chemistry; D012645:Selenomethionine / Q000737:chemistry; D018089:Superantigens; D013997:Time Factors
chemical_list: D000941:Antigens; D000942:Antigens, Bacterial; D008934:Mitogens; C052996:Mycoplasma arthritidis mitogen; D010455:Peptides; D011506:Proteins; D011994:Recombinant Proteins; D018089:Superantigens; D011092:Polyethylene Glycols; D012645:Selenomethionine; D005982:Glutathione Transferase