Galectin-13, a different prototype galectin, does not bind beta-galacto-sides and forms dimers via intermolecular disulfide bridges between Cys-136 and Cys-138.
Su, J., Wang, Y., Si, Y., Gao, J., Song, C., Cui, L., Wu, R., Tai, G., Zhou, Y.(2018) Sci Rep 8: 980-980
- PubMed: 29343868 
- DOI: 10.1038/s41598-018-19465-0
- Primary Citation of Related Structures:  
5XG7, 5XG8, 5Y03 - PubMed Abstract: 
During pregnancy, placental protein-13 (galectin-13) is highly expressed in the placenta and fetal tissue, and less so in maternal serum that is related to pre-eclampsia. To understand galectin-13 function at the molecular level, we solved its crystal structure and discovered that its dimer is stabilized by two disulfide bridges between Cys136 and Cys138 and six hydrogen bonds involving Val135, Val137, and Gln139 ...