ID   3.2.1.178
DE   beta-porphyranase.
AN   endo-beta-porphyranase.
AN   porphyranase.
CA   Hydrolysis of beta-D-galactopyranose-(1->4)-alpha-L-galactopyranose-6-
CA   sulfate linkages in porphyran.
CC   -!- The backbone of porphyran consists largely (approximately 70%) of
CC       (1->3)-linked beta-D-galactopyranose followed by (1->4)-linked alpha-
CC       L-galactopyranose-6-sulfate [the other 30% are mostly agarobiose
CC       repeating units of (1->3)-linked beta-D-galactopyranose followed by
CC       (1->4)-linked 3,6-anhydro-alpha-L-galactopyranose].
CC   -!- This enzyme cleaves the (1->4) linkages between beta-D-
CC       galactopyranose and alpha-L-galactopyranose-6-sulfate, forming mostly
CC       the disaccharide alpha-L-galactopyranose-6-sulfate-(1->3)-beta-D-
CC       galactose, although some longer oligosaccharides of even number of
CC       residues are also observed.
CC   -!- Since the enzyme is inactive on the non-sulfated agarose portion of
CC       the porphyran backbone, some agarose fragments are also included in
CC       the products.
CC   -!- Methylation of the D-galactose prevents the enzyme from Zobellia
CC       galactanivorans, but not that from Wenyingzhuangia fucanilytica, from
CC       binding at position -1.
DR   B5CY96, PORA_PHOPM ;  D7GXG0, PORA_ZOBGA ;  B5CY92, PORB_PHOPM ;
DR   D7GXF9, PORB_ZOBGA ;  D7GXG1, PORC_ZOBGA ;  D7GXG2, PORD_ZOBGA ;
DR   D7GXG3, PORE_ZOBGA ;
//