We have crystallized one AAL mutant that has been proved to have stronger affinity towards a1-6 bound fucose. We were able to collect several datasets of high quality with resolution up to 1.09A. The detailed insight into the structure revealed the principal of the affinity change, shading the light upon variability of AAL’s binding sites differences. Furthermore, we utilized in silico approach to describe the contribution of particular amino acids in each of five AAL's binding sites.