EC	3.2.1.89
Accepted name:	arabinogalactan endo-β-1,4-galactanase
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 3.2.1.181, galactan endo-β-1,3-galactanase.
References:	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]
[EC 3.2.1.89 created 1976, modified 2012]