4xbl
From Proteopedia
Crystal Structure of Human Galectin-1 in Complex with Type 1 N-acetyllactosamine
Structural highlights
Function[LEG1_HUMAN] May regulate apoptosis, cell proliferation and cell differentiation. Binds beta-galactoside and a wide array of complex carbohydrates. Inhibits CD45 protein phosphatase activity and therefore the dephosphorylation of Lyn kinase.[1] [2] Publication Abstract from PubMedGalectins represent beta-galactoside-binding proteins and are known to bind Galbeta1-3/4GlcNAc disaccharides (abbreviated as LN1 and LN2, respectively). Despite high sequence and structural homology shared by the carbohydrate recognition domain (CRD) of all galectin members, how each galectin displays different sugar-binding specificity still remains ambiguous. Herein we provided the first structural evidence of human galectins-1, 3-CRD and 7 in complex with LN1. Galectins-1 and 3 were shown to have higher affinity for LN2 than for LN1, while galectin-7 displayed the reversed specificity. In comparison with the previous LN2-complexed structures, the results indicated that the average glycosidic torsion angle of galectin-bound LN1 (psiLN1 approximately 135 degrees ) was significantly differed from that of galectin-bound LN2 (psiLN2 approximately -108 degrees ), i.e. the GlcNAc moiety adopted a different orientation to maintain essential interactions. Furthermore, we also identified an Arg-Asp/Glu-Glu-Arg salt-bridge network and the corresponding loop (to position the second Asp/Glu residue) critical for the LN1/2-binding preference. Structural Basis Underlying the Binding Preference of Human Galectins-1, -3 and -7 for Galbeta1-3/4GlcNAc.,Hsieh TJ, Lin HY, Tu Z, Huang BS, Wu SC, Lin CH PLoS One. 2015 May 6;10(5):e0125946. doi: 10.1371/journal.pone.0125946., eCollection 2015. PMID:25945972[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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