Alpha-L-rhamnosidase which is able to degrade p-nitrophenyl-alpha-L-rhamnopyranoside (PNP-Rha) in vitro. Releases L-rhamnose from citrus flavonoids such as naringin, rutin and hesperidin, and the arabinogalactan-protein (AGP) gum arabic. AGPs are a family of proteoglycans that are localized on the cell surfaces of higher plants. Cleaves both the alpha-1,6 and the alpha-1,2-linked rhamnosyl residues. Hydrolysis of terminal non-reducing alpha-L-rhamnose residues in alpha-L-rhamnosides. kcat is 1.93 sec(-1) with p-nitrophenyl-alpha-L-rhamnopyranoside as substrate. Optimum pH is 6. Optimum temperature is 50 degrees Celsius. The carbohydrate-binding module-67 (CBM67) binds L-rhamnose, it does not bind L-galactose or L-fucose, demonstrating that stereochemistry of the sugar at C4 and/or C2 are important specificity determinants. Also, removal of calcium through chelation or mutation abrogates L-rhamnose binding, confirming the importance of calcium in the binding of its ligand. Belongs to the glycosyl hydrolase 78 family.