Galectin-10: a new structural type of prototype galectin dimer and effects on saccharide ligand binding.
Su, J., Gao, J., Si, Y., Cui, L., Song, C., Wang, Y., Wu, R., Tai, G., Zhou, Y.(2018) Glycobiology 28: 159-168
- PubMed: 29293962 
- DOI: https://doi.org/10.1093/glycob/cwx107
- Primary Citation of Related Structures:  
5XRG, 5XRH, 5XRI, 5XRJ, 5XRK, 5XRL, 5XRM, 5XRN, 5XRO, 5XRP, 5YT4 - PubMed Abstract: 
Galectin-10 (Gal-10) which forms Charcot-Leyden crystals in vivo, is crucial to regulating lymph cell function. Here, we solved the crystal structures of Gal-10 and eight variants at resolutions of 1.55-2.00 Å. Structural analysis and size exclusion chromatography demonstrated that Gal-10 dimerizes with a novel global shape that is different from that of other prototype galectins (e.g., Gal-1, -2 and -7). In the Gal-10 dimer, Glu33 from one subunit modifies the carbohydrate-binding site of another, essentially inhibiting disaccharide binding. Nevertheless, glycerol (and possibly other small hydroxylated molecules) can interact with residues at the ligand binding site, with His53 being the most crucial for binding. Alanine substitution of the conserved Trp residue (Trp72) that is crucial to saccharide binding in other galectins, actually leads to enhanced erythrocyte agglutination, suggesting that Trp72 negatively regulates Gal-10 ligand binding. Overall, our crystallographic and biochemical results provide insight into Gal-10 ligand binding specificity.
Organizational Affiliation: 
Jilin Province Key Laboratory for Chemistry and Biology of Natural Drugs in Changbai Mountain, The School of Life Sciences, Northeast Normal University, Changchun 130024, China.