title: Crystallization and preliminary X-ray diffraction analysis of mouse galectin-4 N-terminal carbohydrate recognition domain in complex with lactose.
abstract: Galectin-4 is thought to play a role in the process of tumour conversion of cells of the alimentary tract and the breast tissue; however, its exact function remains unknown. With the aim of elucidating the structural basis of mouse galectin-4 (mGal-4) binding specificity, we have undertaken X-ray analysis of the N-terminal domain, CRD1, of mGal-4 in complex with lactose (the basic building block of known galectin-4 carbohydrate ligands). Crystals of CRD1 in complex with lactose were obtained using vapour-diffusion techniques. The crystals belong to tetragonal space group P42(1)2 with unit-cell parameters a = 91.1, b = 91.16, c = 57.10 A and preliminary X-ray diffraction data were collected to 3.2 A resolution. An optimized crystallization procedure and cryocooling protocol allowed us to extend resolution to 2.1 A. Structure refinement is currently under way; the initial electron-density maps clearly show non-protein electron density in the vicinity of the carbohydrate binding site, indicating the presence of one lactose molecule. The structure will help to improve understanding of the binding specificity and function of the potential colon cancer marker galectin-4.
authors.affiliation: Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 37 Praha 6, Czech Republic.
authors.forename: Veronika
authors.initials: V
authors.lastname: Krejciríková
authors.forename: Milan
authors.initials: M
authors.lastname: Fábry
authors.forename: Vladimíra
authors.initials: V
authors.lastname: Marková
authors.forename: Petr
authors.initials: P
authors.lastname: Malý
authors.forename: Pavlína
authors.initials: P
authors.lastname: Rezácová
authors.forename: Jirí
authors.initials: J
authors.lastname: Brynda
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D001665:Binding Sites; D014408:Biomarkers, Tumor / Q000737:chemistry / Q000378:metabolism; D003110:Colonic Neoplasms / Q000737:chemistry / Q000378:metabolism; D003460:Crystallization; D037541:Galectin 4 / Q000737:chemistry* / Q000378:metabolism*; D007785:Lactose / Q000737:chemistry / Q000378:metabolism*; D008024:Ligands; D051379:Mice; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D017434:Protein Structure, Tertiary; D014961:X-Ray Diffraction
chemical_list: D014408:Biomarkers, Tumor; D037541:Galectin 4; D008024:Ligands; D010446:Peptide Fragments; D007785:Lactose