Members of this family, which are present in fungal alpha-L-arabinofuranosidase B, adopt a beta-sandwich fold similar to that of Concanavalin A-like lectins/glucanase. The beta-sandwich fold consists of two anti-parallel beta-sheets with seven and and six strands, respectively. In addition, there are four helices outside of the beta-strands. The beta-sandwich strands are closely packed and curved with a jelly roll topology, creating a small catalytic pocket. The domain catalyses the hydrolysis of alpha-1,2-, alpha-1,3- and alpha-1,5-L-arabinofuranosidic bonds in L-arabinose-containing hemicelluloses such as arabinoxylan and L-arabinan [1].

1: Crystal structure of a family 54 alpha-L-arabinofuranosidase reveals a novel carbohydrate-binding module that can bind arabinose. Miyanaga A, Koseki T, Matsuzawa H, Wakagi T, Shoun H, Fushinobu S; J Biol Chem. 2004;279:44907-44914. PMID:15292273