title: The crystal structure of the Calystegia sepium agglutinin reveals a novel quaternary arrangement of lectin subunits with a beta-prism fold.
abstract: The high number of quaternary structures observed for lectins highlights the important role of these oligomeric assemblies during carbohydrate recognition events. Although a large diversity in the mode of association of lectin subunits is frequently observed, the oligomeric assemblies of plant lectins display small variations within a single family. The crystal structure of the mannose-binding jacalin-related lectin from Calystegia sepium (Calsepa) has been determined at 1.37-A resolution. Calsepa exhibits the same beta-prism fold as identified previously for other members of the family, but the shape and the hydrophobic character of its carbohydrate-binding site is unlike that of other members, consistent with surface plasmon resonance analysis showing a preference for methylated sugars. Calsepa reveals a novel dimeric assembly markedly dissimilar to those described earlier for Heltuba and jacalin but mimics the canonical 12-stranded beta-sandwich dimer found in legume lectins. The present structure exemplifies the adaptability of the beta-prism building block in the evolution of plant lectins and highlights the biological role of these quaternary structures for carbohydrate recognition.
authors.affiliation: AFMB-CNRS, CNRS UMR6098, F13402 Marseille Cedex 20, France. yves@afmb.cnrs-mrs.fr
authors.forename: Yves
authors.initials: Y
authors.lastname: Bourne
authors.forename: Véronique
authors.initials: V
authors.lastname: Roig-Zamboni
authors.forename: Annick
authors.initials: A
authors.lastname: Barre
authors.forename: Willy J
authors.initials: WJ
authors.lastname: Peumans
authors.forename: Corinne Houlès
authors.initials: CH
authors.lastname: Astoul
authors.forename: Els J M
authors.initials: EJ
authors.lastname: Van Damme
authors.forename: Pierre
authors.initials: P
authors.lastname: Rougé
mesh_terms: D000595:Amino Acid Sequence; D031253:Calystegia / Q000737:chemistry*; D018360:Crystallography, X-Ray; D007700:Kinetics; D037102:Lectins / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000737:chemistry; D037121:Plant Lectins / Q000737:chemistry* / Q000302:isolation & purification; D017510:Protein Folding; D020836:Protein Structure, Quaternary; D021122:Protein Subunits / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D037102:Lectins; D009005:Monosaccharides; D037121:Plant Lectins; D021122:Protein Subunits