This is the C-terminal domain found in ExoP (exo-1,3/1,4-beta-glucanase) from Pseudoalteromonas. This domain contains a beta-sandwich fold which is common in glycosyl hydrolases (GH7, 11, 12 and 16) and in some 23 carbohydrate-binding modules. It is suggested that the main role of this domain is to provide structural stability necessary for ExoP activity, however no substrate-binding role has been shown [1].

1: Structure and activity of exo-1,3/1,4-beta-glucanase from marine bacterium Pseudoalteromonas sp. BB1 showing a novel C-terminal domain. Nakatani Y, Cutfield SM, Cowieson NP, Cutfield JF; FEBS J. 2012;279:464-478. PMID:22129429