This domain is found at the C-terminus of glycosyl hydrolase family 79 proteins. It's function is not yet known [1].

1: Structural and biochemical characterization of glycoside hydrolase family 79 beta-glucuronidase from Acidobacterium capsulatum. Michikawa M, Ichinose H, Momma M, Biely P, Jongkees S, Yoshida M, Kotake T, Tsumuraya Y, Withers SG, Fujimoto Z, Kaneko S; J Biol Chem. 2012;287:14069-14077. PMID:22367201