1qos

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spinqualitylabelsall models 1qos, resolution 2.95Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

LECTIN UEA-II COMPLEXED WITH CHITOBIOSE

Overview

Protein-carbohydrate interactions are the language of choice for inter-, cellular communication. The legume lectins form a large family of, homologous proteins that exhibit a wide variety of carbohydrate, specificities. The legume lectin family is therefore highly suitable as a, model system to study the structural principles of protein-carbohydrate, recognition. Until now, structural data are only available for two, specificity families: Man/Glc and Gal/GalNAc. No structural data are, available for any of the fucose or chitobiose specific lectins.The crystal, structure of Ulex europaeus (UEA-II) is the first of a legume lectin, belonging to the chitobiose specificity group. The complexes with, N-acetylglucosamine, galactose and fucosylgalactose show a promiscuous, primary binding site capable of accommodating both N-acetylglucos amine or, galactose in the primary binding site. The hydrogen bonding network in, these complexes can be considered suboptimal, in agreement with the low, affinities of these sugars. In the complexes with chitobiose, lactose and, fucosyllactose this suboptimal hydrogen bonding network is compensated by, extensive hydrophobic interactions in a Glc/GlcNAc binding subsite. UEA-II, thus forms the first example of a legume lectin with a promiscuous binding, site and illustrates the importance of hydrophobic interactions in, protein-carbohydrate complexes. Together with other known legume lectin, crystal structures, it shows how different specificities can be grafted, upon a conserved structural framework.

About this Structure

1QOS is a Single protein structure of sequence from Ulex europaeus with NAG, MN and CA as ligands. Full crystallographic information is available from OCA.

Reference

Structural basis of carbohydrate recognition by lectin II from Ulex europaeus, a protein with a promiscuous carbohydrate-binding site., Loris R, De Greve H, Dao-Thi MH, Messens J, Imberty A, Wyns L, J Mol Biol. 2000 Aug 25;301(4):987-1002. PMID:10966800

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