This domain is found at the C-terminal end of the group of bacterial glycosyl hydrolases 109, including Alpha-N-acetylgalactosaminidase from Elizabethkingia meningoseptica. This domain shows a large open-faced, seven-stranded, anti-parallel beta-sheet, adjacent to nine alpha-helices and an alpha-helical bundle covering the dinucleotide-binding tunnel [1].

1: Bacterial glycosidases for the production of universal red blood cells. Liu QP, Sulzenbacher G, Yuan H, Bennett EP, Pietz G, Saunders K, Spence J, Nudelman E, Levery SB, White T, Neveu JM, Lane WS, Bourne Y, Olsson ML, Henrissat B, Clausen H; Nat Biotechnol. 2007;25:454-464. PMID:17401360