1JOT

STRUCTURE OF THE LECTIN MPA COMPLEXED WITH T-ANTIGEN DISACCHARIDE

Summary for 1JOT

• Entry DOI: 10.2210/pdb1jot/pdb
• Related PRD ID: PRD_900084
• Descriptor: AGGLUTININ, beta-D-galactopyranose-(1-3)-2-acetamido-2-deoxy-alpha-D-galactopyranose, ... (4 entities in total)
• Functional Keywords: multi-wavelength anomalous diffraction (mad), t-antigen, lectin, maclura pomifera, beta prism
• Biological source: Maclura pomifera (Osage orange); More
• Total number of polymer chains: 2
• Total formula weight: 17296.32

Authors

Lee, X.,Thompson, A.,Zhang, Z.,Hoa, T.-T.,Biesterfeldt, J.,Ogata, C.,Xu, L.,Johnston, R.A.Z.,Young, N.M. (deposition date: 1997-12-05, release date: 1998-12-30, Last modification date: 2024-04-03)

Primary citation

Lee, X.,Thompson, A.,Zhang, Z.,Ton-that, H.,Biesterfeldt, J.,Ogata, C.,Xu, L.,Johnston, R.A.,Young, N.M.
Structure of the complex of Maclura pomifera agglutinin and the T-antigen disaccharide, Galbeta1,3GalNAc.
J.Biol.Chem., 273:6312-6318, 1998

PubMed Abstract: Maclura pomifera agglutinin is a tetrameric plant seed lectin with high affinity for the tumor-associated T-antigen disaccharide, Galbeta1,3GalNAcalpha, and hence for many O-linked glycopeptide structures. Unlike members of most lectin families, it lacks both metal ions and Cys residues. The structure of its complex with Galbeta1,3GalNAc was determined to 2.2 by first using multiwavelength anomalous diffraction with a lead derivative of the native protein, and then using molecular replacement with the unrefined structure as a model to solve the structure of the complex. The subunits share the beta-prism architecture and three-fold pseudo-symmetry of the related lectin jacalin, with the 21-residue beta-chains in the center of the tetramer. Interactions with the GalNAc predominate in the binding of the disaccharide. It forms a network of H-bonds with only one side chain, from an Asp residue, the amino group of the N-terminal Gly of the alpha-chain, and peptide backbone atoms of two aromatic residues. The Gal moiety does not H-bond directly with residues in the same monomer, i.e. there is no true subsite for it, but there are interactions through two water molecules. In the crystal, it interacts with residues in the binding site of an adjacent tetramer. The minimum energy conformation expected for the disaccharide is retained, despite its mediating the tetramer-tetramer interactions in the crystal packing. The resulting lattice is comparable to those seen for complexes of other lectins with branched glycopeptides.

PubMed: 9497359
DOI: 10.1074/jbc.273.11.6312

Experimental method

X-RAY DIFFRACTION (2.2 Å)