2d3s

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spinqualitylabelsall models 2d3s, resolution 2.35Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal Structure of basic winged bean lectin with Tn-antigen

Overview

The crystal structure of winged bean basic agglutinin in complex with, GalNAc-alpha-O-Ser (Tn-antigen) has been elucidated at 2.35 angstroms, resolution in order to characterize the mode of binding of Tn-antigen with, the lectin. The Gal moiety occupies the primary binding site and makes, interactions similar to those found in other Gal/GalNAc specific legume, lectins. The nitrogen and oxygen atoms of the acetamido group of the sugar, make two hydrogen bonds with the protein atoms whereas its methyl group is, stabilized by hydrophobic interactions. A water bridge formed between the, terminal oxygen atoms of the serine residue of the Tn-antigen and the side, chain oxygen atom of Asn128 of the lectin increase the affinity of the, lectin for Tn-antigen compared to that for GalNAc. A comparison with the, available structures reveals that while the interactions of the glyconic, part of the antigen are conserved, the mode of stabilization of the serine, residue differs and depends on the nature of the protein residues in its, vicinity. The structure provides a qualitative explanation for the, thermodynamic parameters of the complexation of the lectin with, Tn-antigen. Modeling studies indicate the possibility of an additional, hydrogen bond with the lectin when the antigen is part of a glycoprotein.

About this Structure

2D3S is a Single protein structure of sequence from Psophocarpus tetragonolobus with NAG, CA, MN and TNR as ligands. Full crystallographic information is available from OCA.

Reference

Structural basis for the specificity of basic winged bean lectin for the Tn-antigen: a crystallographic, thermodynamic and modelling study., Kulkarni KA, Sinha S, Katiyar S, Surolia A, Vijayan M, Suguna K, FEBS Lett. 2005 Dec 19;579(30):6775-80. Epub 2005 Nov 21. PMID:16310781

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