5DUV

Crystal structure of the human galectin-4 N-terminal carbohydrate recognition domain in complex with lactose

Summary for 5DUV

• Entry DOI: 10.2210/pdb5duv/pdb
• Related: 5DUU 5DUW 5DUX
• Related PRD ID: PRD_900004
• Descriptor: Galectin-4, beta-D-galactopyranose-(1-4)-beta-D-glucopyranose, CALCIUM ION, ... (5 entities in total)
• Functional Keywords: galectin-4, lectin, lactose, sugar-binding protein, sugar binding protein
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 4
• Total formula weight: 71543.24

Authors

Bum-Erdene, K.,Blanchard, H. (deposition date: 2015-09-21, release date: 2016-02-17, Last modification date: 2023-09-27)

Primary citation

Bum-Erdene, K.,Leffler, H.,Nilsson, U.J.,Blanchard, H.
Structural characterisation of human galectin-4 N-terminal carbohydrate recognition domain in complex with glycerol, lactose, 3'-sulfo-lactose, and 2'-fucosyllactose.
Sci Rep, 6:20289-20289, 2016

PubMed Abstract: Galectin-4 is a tandem-repeat galectin with two distinct carbohydrate recognition domains (CRD). Galectin-4 is expressed mainly in the alimentary tract and is proposed to function as a lipid raft and adherens junction stabilizer by its glycan cross-linking capacity. Galectin-4 plays divergent roles in cancer and inflammatory conditions, either promoting or inhibiting each disease progression, depending on the specific pathological condition. The study of galectin-4's ligand-binding profile may help decipher its roles under specific conditions. Here we present the X-ray structures of human galectin-4 N-terminal CRD (galectin-4N) bound to different saccharide ligands. Galectin-4's overall fold and its core interactions to lactose are similar to other galectin CRDs. Galectin-4N recognises the sulfate cap of 3'-sulfated glycans by a weak interaction through Arg45 and two water-mediated hydrogen bonds via Trp84 and Asn49. When galectin-4N interacts with the H-antigen mimic, 2'-fucosyllactose, an interaction is formed between the ring oxygen of fucose and Arg45. The extended binding site of galectin-4N may not be well suited to the A/B-antigen determinants, α-GalNAc/α-Gal, specifically due to clashes with residue Phe47. Overall, galectin-4N favours sulfated glycans whilst galectin-4C prefers blood group determinants. However, the two CRDs of galectin-4 can, to a less extent, recognise each other's ligands.

PubMed: 26828567
DOI: 10.1038/srep20289

Experimental method

X-RAY DIFFRACTION (1.9 Å)