Reaction: The enzyme specifically hydrolyses (1→4)-β-D-galactosidic linkages in type I arabinogalactans.
Other name(s): endo-1,4-β-galactanase; galactanase (ambiguous); arabinogalactanase; ganB (gene name)
Systematic name: arabinogalactan 4-β-D-galactanohydrolase
Comments: This enzyme, isolated from the bacterium Bacillus subtilis, hydrolyses the β(1→4) bonds found in type I plant arabinogalactans, which are a component of the primary cell walls of dicots. The predominant product is a tetrasaccharide. cf. EC 18.104.22.168, galactan endo-β-1,3-galactanase.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 58182-40-4
1. Emi, S. and Yamamoto, T. Purification and properties of several galactanases of Bacillus subtilis var. amylosacchariticus. Agric. Biol. Chem. 36 (1972) 1945-1954.
2. Labavitch, J.M., Freeman, L.E. and Albersheim, P. Structure of plant cell walls. Purification and characterization of a β-1,4-galactanase which degrades a structural component of the primary cell walls of dicots. J. Biol. Chem. 251 (1976) 5904-5910. [PMID: 823153]
3. Shipkowski, S. and Brenchley, J.E. Bioinformatic, genetic, and biochemical evidence that some glycoside hydrolase family 42 β-galactosidases are arabinogalactan type I oligomer hydrolases. Appl. Environ. Microbiol. 72 (2006) 7730-7738. [PMID: 17056685]