1LU2
DOLICHOS BIFLORUS SEED LECTIN IN COMPLEX WITH THE BLOOD GROUP A TRISACCHARIDE
1LU2 の概要
エントリーDOI | 10.2210/pdb1lu2/pdb |
分子名称 | LECTIN, 2-acetamido-2-deoxy-alpha-D-galactopyranose, CALCIUM ION, ... (4 entities in total) |
機能のキーワード | legume lectins, dolichos biflorus seed lectin, sugar binding, lectin |
由来する生物種 | Vigna unguiculata subsp. cylindrica (horse gram) |
タンパク質・核酸の鎖数 | 2 |
化学式量合計 | 54862.60 |
構造登録者 | Hamelryck, T.W.,Loris, R.,Bouckaert, J.,Strecker, G.,Imberty, A.,Fernandez, E.,Wyns, L.,Etzler, M.E. (登録日: 1998-07-30, 公開日: 1998-12-09, 最終更新日: 2024-05-22) |
主引用文献 | Hamelryck, T.W.,Loris, R.,Bouckaert, J.,Dao-Thi, M.H.,Strecker, G.,Imberty, A.,Fernandez, E.,Wyns, L.,Etzler, M.E. Carbohydrate binding, quaternary structure and a novel hydrophobic binding site in two legume lectin oligomers from Dolichos biflorus. J.Mol.Biol., 286:1161-1177, 1999 Cited by PubMed Abstract: The seed lectin (DBL) from the leguminous plant Dolichos biflorus has a unique specificity among the members of the legume lectin family because of its high preference for GalNAc over Gal. In addition, precipitation of blood group A+H substance by DBL is slightly better inhibited by a blood group A trisaccharide (GalNAc(alpha1-3)[Fuc(alpha1-2)]Gal) containing pentasaccharide, and about 40 times better by the Forssman disaccharide (GalNAc(alpha1-3)GalNAc) than by GalNAc. We report the crystal structures of the DBL-blood group A trisaccharide complex and the DBL-Forssman disaccharide complex.A comparison with the binding sites of Gal-binding legume lectins indicates that the low affinity of DBL for Gal is due to the substitution of a conserved aromatic residue by an aliphatic residue (Leu127). Binding studies with a Leu127Phe mutant corroborate these conclusions. DBL has a higher affinity for GalNAc because the N-acetyl group compensates for the loss of aromatic stacking in DBL by making a hydrogen bond with the backbone amide group of Gly103 and a hydrophobic contact with the side-chains of Trp132 and Tyr104. Some legume lectins possess a hydrophobic binding site that binds adenine and adenine-derived plant hormones, i.e. cytokinins. The exact function of this binding site is unknown, but adenine/cytokinin-binding legume lectins might be involved in storage of plant hormones or plant growth regulation. The structures of DBL in complex with adenine and of the dimeric stem and leaf lectin (DB58) from the same plant provide the first structural data on these binding sites. Both oligomers possess an unusual architecture, featuring an alpha-helix sandwiched between two monomers. In both oligomers, this alpha-helix is directly involved in the formation of the hydrophobic binding site. DB58 adopts a novel quaternary structure, related to the quaternary structure of the DBL heterotetramer, and brings the number of know legume lectin dimer types to four. PubMed: 10047489DOI: 10.1006/jmbi.1998.2534 主引用文献が同じPDBエントリー |
実験手法 | X-RAY DIFFRACTION (2.8 Å) |
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