This is the C-terminal domain found in Bacteroides plebeius of proteins such as beta-porphyranase A (BPA), a beta-galactanase that cleaves the beta-1,4 glycosidic bond . Porphyranase degrade red seaweed glycans. This domain adopts a beta sandwich shape [1].

1: Bacteria of the human gut microbiome catabolize red seaweed glycans with carbohydrate-active enzyme updates from extrinsic microbes. Hehemann JH, Kelly AG, Pudlo NA, Martens EC, Boraston AB; Proc Natl Acad Sci U S A. 2012;109:19786-19791. PMID:23150581