2SBA

SOYBEAN AGGLUTININ COMPLEXED WITH 2,6-PENTASACCHARIDE

「1SBA」から置き換えられました

2SBA の概要

• エントリーDOI: 10.2210/pdb2sba/pdb
• 分子名称: Lectin, beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, MANGANESE (II) ION, ... (5 entities in total)
• 機能のキーワード: lectin (agglutinin), sugar binding protein
• 由来する生物種: Glycine max (soybeans)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 28074.18

構造登録者

Dessen, A.,Gupta, D.,Sabesan, S.,Brewer, C.F.,Sacchettini, J.C. (登録日: 1998-12-03, 公開日: 1998-12-09, 最終更新日: 2023-08-30)

主引用文献

Dessen, A.,Gupta, D.,Sabesan, S.,Brewer, C.F.,Sacchettini, J.C.
X-ray crystal structure of the soybean agglutinin cross-linked with a biantennary analog of the blood group I carbohydrate antigen.
Biochemistry, 34:4933-4942, 1995

PubMed Abstract: Soybean agglutinin (SBA) (Glycine max), which is a tetrameric GalNAc/Gal-specific lectin, has recently been reported to form unique, highly organized cross-linked complexes with a series of naturally occurring and synthetic multiantennary carbohydrates with terminal GalNAc or Gal residues [Gupta, D., Bhattacharyya, L., Fant, J., Macaluso, F., Sabesan, S., & Brewer, C. F. (1994) Biochemistry 33, 7495-7504]. In order to elucidate the nature of these complexes, the X-ray crystallographic structure of SBA cross-linked with a biantennary analog of the blood group I carbohydrate antigen is reported. The structure reveals that lattice formation is promoted uniquely by the bridging action of the bivalent pentasaccharide (beta-LacNAc)2Gal-beta-R, where R is -O(CH2)5COOCH3 and the beta-LacNAc moieties are linked to the 2 and 6 positions of the core Gal. The structure of SBA complexed with the synthetic biantennary pentasaccharide has thus been determined by molecular replacement techniques and refined at 2.6 A resolution to an R value of 20.1%. The crystals are hexagonal with a P6(4)22 space group, which differs significantly from that of crystals of the free protein. In the structure, each monomeric asymmetric unit contains a Man9 oligomannose-type chain at Asn 75, with only the first two GlcNAc residues visible. The overall tertiary structure of the SBA subunit is similar to that of other legume lectins as well as certain animal lectins. However, the dimer interface in the SBA tetramer is unusual in that only one complete peptide chain is sterically permitted, thus requiring juxtapositioning of one C-terminal fragmented subunit together with an intact subunit. Association between SBA tetramers involves binding of the terminal Gal residues of the pentasaccharide at identical sites in each monomer, with the sugar cross-linking to a symmetry-related neighbor molecule. The cross-linking pentasaccharide is in a conformation that possesses a pseudo-2-fold axis of symmetry which lies on a crystallographic 2-fold axis of symmetry of the lattice. Hence, the symmetry properties of the bivalent oligosaccharide as well as the lectin are structural determinants of the lattice. The results are discussed in terms of multidimensional carbohydrate-lectin cross-linked complexes, as well as the signal transduction properties of multivalent lectins.

PubMed: 7711015
DOI: 10.1021/bi00015a004

実験手法

X-RAY DIFFRACTION (2.6 Å)