This domain is found towards the C terminus of Beta-glucuronidase from Formosa agariphila (P17_GH2) and similar proteins mainly from bacteria and fungi. P17_GH2 is involved in the degradation of the polysaccharide ulvan. The function of this domain, which shows an all-beta structure, is unknown [1].

1: A marine bacterial enzymatic cascade degrades the algal polysaccharide ulvan. Reisky L, Prechoux A, Zuhlke MK, Baumgen M, Robb CS, Gerlach N, Roret T, Stanetty C, Larocque R, Michel G, Song T, Markert S, Unfried F, Mihovilovic MD, Trautwein-Schult A, Becher D, Schweder T, Bornscheuer UT, Hehemann JH; Nat Chem Biol. 2019;15:803-812. PMID:31285597