5ava
From Proteopedia
Crystal structure of PHA-E lectin in complex with bisected glycan
Structural highlights
FunctionPHAE_PHAVU This insecticidal carbohydrate-binding lectin is toxic for the cowpea weevil. Publication Abstract from PubMedGlycans normally exist as a dynamic equilibrium of several conformations. A fundamental question concerns how such molecules bind lectins despite disadvantageous entropic loss upon binding. Bisected glycan, a glycan possessing bisecting N-acetylglucosamine (GlcNAc), is potentially a good model for investigating conformational dynamics and glycan-lectin interactions, owing to the unique ability of this sugar residue to alter conformer populations and thus modulate the biological activities. Here we analyzed bisected glycan in complex with two unrelated lectins, Calsepa and PHA-E. The crystal structures of the two complexes show a conspicuous flipped back glycan structure (designated 'back-fold' conformation), and solution NMR analysis also provides evidence of 'back-fold' glycan structure. Indeed, statistical conformational analysis of available bisected and non-bisected glycan structures suggests that bisecting GlcNAc restricts the conformations of branched structures. Restriction of glycan flexibility by certain sugar residues may be more common than previously thought and impinges on the mechanism of glycoform-dependent biological functions. Atomic visualization of a flipped-back conformation of bisected glycans bound to specific lectins.,Nagae M, Kanagawa M, Morita-Matsumoto K, Hanashima S, Kizuka Y, Taniguchi N, Yamaguchi Y Sci Rep. 2016 Mar 14;6:22973. doi: 10.1038/srep22973. PMID:26971576[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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