1tp8

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spinqualitylabelsall models 1tp8, resolution 3.0Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL STRUCTURE OF A GALACTOSE SPECIFIC LECTIN FROM ARTOCARPUS HIRSUTA IN COMPLEX WITH METHYL-a-D-GALACTOSE

Overview

Based on their carbohydrate specificity, the jacalin family of lectins can, be divided into two groups: galactose-specific and mannose-specific. The, former are cytoplasmic proteins, whereas the latter are localized in the, storage vacuoles of cells. It has been proposed that the, post-translational modification in some of the lectins that splits their, polypeptide chains into two may be crucial for galactose specificity. The, mannose-specific members of the family are single-chain proteins that lack, the above modification. Although the galactose-specific and the, mannose-specific jacalin-type lectins differ in their sequences, they, share a common fold: the beta-prism I fold, which is characteristic of, Moraceae plant lectins. Here, two crystal structures of a jacalin-related, lectin from Artocarpus hirsuta, which is specific for galactose, in, complex with methyl-alpha-D-galactose are reported. The lectin, crystallized in two orthorhombic forms and one hexagonal form under, similar conditions. The crystals had an unusually high solvent content., The structure was solved using the molecular-replacement method using the, jacalin structure as a search model. The two orthorhombic forms were, refined using data to 2.5 and 3.0 A resolution, respectively. The, structures of the A. hirsuta lectin and jacalin are identical. In, orthorhombic form I the crystal packing provides three different, micro-environments for sugar binding in the same crystal. The observed, difference in the specificity for oligosaccharides between the A. hirsuta, lectin and jacalin could only be explained based on differences in the, molecular associations in the packing and variation of the C-terminal, length of the beta-chain. The observed insecticidal activity of A. hirsuta, lectin may arise from its similar fold to domain II of the unrelated, delta-endotoxin from Bacillus thuringiensis.

About this Structure

1TP8 is a Protein complex structure of sequences from Artocarpus hirsutus with AMG as ligand. Full crystallographic information is available from OCA.

Reference

Two orthorhombic crystal structures of a galactose-specific lectin from Artocarpus hirsuta in complex with methyl-alpha-D-galactose., Rao KN, Suresh CG, Katre UV, Gaikwad SM, Khan MI, Acta Crystallogr D Biol Crystallogr. 2004 Aug;60(Pt 8):1404-12. Epub 2004, Jul 21. PMID:15272163

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