Lectins are involved in many recognition events at the molecular or cellular level. These fungal lectins, such as Aleuria aurantia lectin (AAL, Swiss:P18891), specifically recognise fucosylated glycans. AAL is a dimeric protein, with each monomer being organised into a six-bladed beta-propeller fold and a small antiparallel two-stranded beta-sheet. The beta-propeller fold is important in fucose recognition; five binding pockets are found between the propeller blades. The small beta-sheet, on the other hand, is involved in the dimerisation process [1].

1: Crystal structure of fungal lectin: six-bladed beta-propeller fold and novel fucose recognition mode for Aleuria aurantia lectin. Wimmerova M, Mitchell E, Sanchez JF, Gautier C, Imberty A; J Biol Chem 2003;278:27059-27067. PMID:12732625