Reaction: Hydrolysis of α-D-Galp-(1→3)-L-Araf disaccharides from non-reducing terminals in branches of type II arabinogalactan attached to proteins.
Glossary: Araf = arabinofuranose
Arap = arabinopyranose
Galp = galactopyranose
Other name(s): 3-O-α-D-galactosyl-α-L-arabinofuranosidase
Systematic name: type II arabinogalactan exo α-(1,3)-[α-D-galactosyl-(1→3)-L-arabinofuranose] hydrolase (non-reducing end)
Comments: The enzyme, characterized from the bacterium Bifidobacterium longum, specifically hydrolyses α-D-Galp-(1→3)-L-Araf disaccharides from the non-reducing terminal of arabinogalactan using an exo mode of action. It is particularly active with gum arabic arabinogalactan, a type II arabinogalactan produced by acacia trees. The enzyme can also hydrolyse β-L-Arap-(1→3)-L-Araf disaccharides, but this activity is significantly lower.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
1. Sasaki, Y., Horigome, A., Odamaki, T., Xiao, J.Z., Ishiwata, A., Ito, Y., Kitahara, K. and Fujita, K. Characterization of a novel 3-O-α-D-galactosyl-α-L-arabinofuranosidase for the assimilation of gum arabic AGP in Bifidobacterium longum subsp. longum, Appl. Environ. Microbiol. (2021) . [PMID: 33674431]