The enzyme from the fungus Flammulina velutipes (winter mushroom) hydrolyses the beta(1->3) bonds found in type II plant arabinogalactans, which occur in cell walls of dicots and cereals. The enzyme is an endohydrolase, and requires at least 3 contiguous beta-1,3-residues. cf. EC
3.2.1.89, arabinogalactan endo-beta-1,4-galactanase and EC
3.2.1.145, galactan 1,3-beta-galactosidase.