title: Crystallization and preliminary X-ray diffraction studies of the carbohydrate-recognition domain of SIGN-R1, a receptor for microbial polysaccharides and sialylated antibody on splenic marginal zone macrophages.
abstract: SIGN-R1, or CD209b, is a mouse C-type lectin receptor that is expressed at high levels on macrophages in lymphoid tissues, especially within the marginal zone of the spleen. SIGN-R1 can bind and mediate the uptake of various microbial polysaccharides, including dextrans, lipopolysaccharides and pneumococcal capsular polysaccharides. It has been shown that SIGN-R1 mediates the clearance of encapsulated pneumococcus, complement fixation via binding C1q independent of antibody and innate resistance to pneumococcal infection. Recently, SIGN-R1 has also been demonstrated to bind sialylated antibody and mediate its activity to suppress autoimmunity. The carbohydrate-recognition domain (CRD) of SIGN-R1 has been cloned and overexpressed in a soluble secretory form in mammalian Chinese hamster ovary (CHO) cells. The CRD protein of SIGN-R1 was purified from CHO cell-culture supernatant and concentrated for crystallization using the hanging-drop vapour-diffusion method at 291 K. Crystals grew from a mixture of 2 M ammonium sulfate in 0.1 M bis-tris pH 5.5. Single crystals, which belonged to the monoclinic space group C2 with unit-cell parameters a = 146.72, b = 92.77, c = 77.06 A, beta = 121.66 degrees , allowed the collection of a full X-ray data set to a maximum resolution of 1.87 A.
authors.affiliation: Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain.
authors.forename: Noella
authors.initials: N
authors.lastname: Silva-Martin
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Schauer
authors.forename: Chae Gyu
authors.initials: CG
authors.lastname: Park
authors.forename: Juan A
authors.initials: JA
authors.lastname: Hermoso
mesh_terms: D000818:Animals; D000906:Antibodies / Q000378:metabolism*; D016466:CHO Cells; D015815:Cell Adhesion Molecules / Q000737:chemistry* / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D018360:Crystallography, X-Ray; D037181:Lectins, C-Type / Q000737:chemistry* / Q000378:metabolism; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D011134:Polysaccharides / Q000378:metabolism*; D011487:Protein Conformation; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013154:Spleen / Q000276:immunology / Q000378:metabolism*; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin
chemical_list: D000906:Antibodies; D015815:Cell Adhesion Molecules; D037181:Lectins, C-Type; D011134:Polysaccharides; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin