4XBQ

Crystal Structure of Human Galectin-7 in Complex with Type 1 N-acetyllactosamine

Summary for 4XBQ

• Entry DOI: 10.2210/pdb4xbq/pdb
• Related: 4XBL 4XBN
• Descriptor: Galectin-7, beta-D-galactopyranose-(1-3)-2-acetamido-2-deoxy-beta-D-glucopyranose (3 entities in total)
• Functional Keywords: complex, human galectin-7, type 1 lacnac, sugar binding protein
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 2
• Total formula weight: 35041.14

Authors

Hsieh, T.J.,Lin, H.Y.,Lin, C.H. (deposition date: 2014-12-17, release date: 2015-05-20, Last modification date: 2023-11-08)

Primary citation

Hsieh, T.J.,Lin, H.Y.,Tu, Z.,Huang, B.S.,Wu, S.C.,Lin, C.H.
Structural Basis Underlying the Binding Preference of Human Galectins-1, -3 and -7 for Gal beta 1-3/4GlcNAc.
Plos One, 10:e0125946-e0125946, 2015

PubMed Abstract: Galectins represent β-galactoside-binding proteins and are known to bind Galβ1-3/4GlcNAc 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 (ψ(LN1) ≈ 135°) was significantly differed from that of galectin-bound LN2 (ψ(LN2 )≈ -108°), 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.

PubMed: 25945972
DOI: 10.1371/journal.pone.0125946

Experimental method

X-RAY DIFFRACTION (2.234 Å)