1DJR

HEAT-LABILE ENTEROTOXIN B-PENTAMER COMPLEXED WITH M-CARBOXYPHENYL-ALPHA-D-GALACTOSE

Summary for 1DJR

• Entry DOI: 10.2210/pdb1djr/pdb
• Related: 1LT5 1LT6 1LTS 3CHB
• Descriptor: HEAT-LABILE ENTEROTOXIN, alpha-D-galactopyranose, GLYCEROL, ... (5 entities in total)
• Functional Keywords: ab5 toxins, cell recognition, six-stranded antiparallel beta-sheet, toxin
• Biological source: Escherichia coli
• Total number of polymer chains: 5
• Total formula weight: 60581.12

Authors

Minke, W.E.,Pickens, J.,Merritt, E.A.,Fan, E.,Verlinde, C.L.M.J.,Hol, W.G.J. (deposition date: 1999-12-03, release date: 2000-06-30, Last modification date: 2024-10-16)

Primary citation

Minke, W.E.,Pickens, J.,Merritt, E.A.,Fan, E.,Verlinde, C.L.,Hol, W.G.
Structure of m-carboxyphenyl-alpha-D-galactopyranoside complexed to heat-labile enterotoxin at 1.3 A resolution: surprising variations in ligand-binding modes.
Acta Crystallogr.,Sect.D, 56:795-804, 2000

PubMed Abstract: In the quest to develop drugs against traveller's diarrhoea and cholera, the structure of the B pentamer of heat-labile enterotoxin (LT) complexed with a new receptor-binding antagonist, m-carboxyphenyl-alpha-D-galactopyranoside, has been determined. The high resolution obtained for this structure allowed anisotropic refinement of the model. It was also now possible to confirm at a near-atomic resolution the structural similarity between the B subunits of LT and the closely related cholera toxin (CT), including the similarity in deviations of planarity of the same peptide unit in LT and CT. The structure of the LT complex clearly revealed different conformations for the m--carboxyphenyl moiety of the ligand in the five B subunits of LT, while the binding modes of the well defined galactopyranoside moieties were identical. In two binding sites the m-carboxyphenyl moiety displayed no significant electron density, demonstrating significant flexibility of this moiety. In a third binding site the m-carboxyphenyl moiety could be modelled unambiguously into the density. The two remaining binding sites were involved in crystal packing contacts and the density for the ligands in these two binding sites clearly revealed different binding modes, of which one conformation was identical to and one completely different from the conformation of m-carboxyphenyl-galactopyranoside in the third subunit. The multiple binding modes observed in the crystal may represent the ensemble of conformations of m-carboxyphenyl-alpha-D-galactopyranoside complexed to LT in solution.

PubMed: 10930826
DOI: 10.1107/S090744490000514X

Experimental method

X-RAY DIFFRACTION (1.3 Å)