This domain is found close to the N-terminus of the Klebsiella starch debranching pullulanase enzyme [1]. The structure of the domain is a beta sandwich fold.

1: Crystal structure of pullulanase: evidence for parallel binding of oligosaccharides in the active site. Mikami B, Iwamoto H, Malle D, Yoon HJ, Demirkan-Sarikaya E, Mezaki Y, Katsuya Y; J Mol Biol. 2006;359:690-707. PMID:16650854