Structural characterization of a lectin from the mushroom Marasmius oreades in complex with the blood group B trisaccharide and calcium.
MOA (Marasmius oreades agglutinin), a lectin isolated from fruiting bodies of the mushroom M. oreades, specifically binds nonreducing terminal Galalpha(1,3)Gal carbohydrates, such as that which occurs in the xenotransplantation epitope Galalpha(1,3)Galbeta(1,4)GlcNAc and the branched blood group B determinant Galalpha(1,3)[Fucalpha(1,2)]Gal. Here, we present the crystal structure of MOA in complex with the blood group B trisaccharide solved at 1.8 A resolution. To our knowledge, this is the first blood-group-B-specific structure reported in complex with a blood group B determinant. The carbohydrate ligand binds to all three binding sites of the N-terminal beta-trefoil domain. Also, in this work, Ca(2+) was included in the crystals, and binding of Ca(2+) to the MOA homodimer altered the conformation of the C-terminal domain by opening up the cleft containing a putative catalytic site.
Department of Chemistry, University of Oslo, Norway. elin.grahn@oru.se
Elin M
EM
Grahn
Harry C
HC
Winter
Hiroaki
H
Tateno
Irwin J
IJ
Goldstein
Ute
U
Krengel
D000494:Allosteric Regulation; D001665:Binding Sites; D002118:Calcium / Q000737:chemistry* / Q000378:metabolism; D018360:Crystallography, X-Ray; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism; D037102:Lectins / Q000737:chemistry* / Q000378:metabolism; D055433:Marasmius / Q000737:chemistry*; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D014312:Trisaccharides / Q000737:chemistry* / Q000378:metabolism
D005656:Fungal Proteins; D037102:Lectins; D014312:Trisaccharides; C406478:blood group B trisaccharide; D002118:Calcium