1pxd

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spinqualitylabelsall models 1pxd, resolution 1.8Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal structure of the complex of jacalin with meso-tetrasulphonatophenylporphyrin.

Overview

The crystal structure of the complex of meso-tetrasulfonatophenylporphyrin, (H(2)TPPS) with jack fruit (Artocarpus integriflora) agglutinin (jacalin), has been determined at 1.8 A resolution. A porphyrin pair is sandwiched, between two symmetry-related jacalin monomers in the crystal, leading to a, cross-linking network of protein molecules. Apart from the stacking, interactions, H(2)TPPS also forms hydrogen bonds, some involving water, bridges, with jacalin at the carbohydrate-binding site. The residues that, are involved in rendering galactopyranoside specificity to jacalin undergo, conformational adjustments in order to accommodate the H(2)TPPS molecule., The water molecules at the carbohydrate-binding site of jacalin cement the, jacalin-porphyrin interactions, optimizing their complementarity., Interactions of porphyrin with jacalin are relatively weak compared with, those observed between galactopyranoside and jacalin, perhaps because the, former largely involves water-mediated hydrogen bonds. While H(2)TPPS, binds to jacalin at the carbohydrate-binding site as in the case of ConA, its mode of interaction with jacalin is very different. H(2)TPPS does not, enter the carbohydrate-binding cavity of jacalin. Instead, it sits over, the binding site. While the porphyrin binding is mediated by replicating, the hydrogen-bonding network of mannopyranoside through the sulfonate, atoms in the case of ConA, the plasticity associated with the, carbohydrate-binding site accommodates the pluripotent porphyrin molecule, in the case of jacalin through an entirely different set of interactions.

About this Structure

1PXD is a Protein complex structure of sequences from Artocarpus integer with SFP as ligand. Full crystallographic information is available from OCA.

Reference

Porphyrin binding to jacalin is facilitated by the inherent plasticity of the carbohydrate-binding site: novel mode of lectin-ligand interaction., Goel M, Anuradha P, Kaur KJ, Maiya BG, Swamy MJ, Salunke DM, Acta Crystallogr D Biol Crystallogr. 2004 Feb;60(Pt 2):281-8. Epub 2004, Jan 23. PMID:14747704

Page seeded by OCA on Wed Nov 21 00:12:23 2007