This entry represents the uncharacterised C-terminal domain of secreted (or membrane-anchored) pullulanases of Gram-negative bacteria and pullulanase-type starch debranching enzymes of plants [1]. Both enzymes hydrolyse alpha-1,6 glycosidic linkages. Pullulan is an unusual, industrially important polysaccharide in which short alpha-1,4 chains (maltotriose) are connected in alpha-1,6 linkages. Enzymes that cleave alpha-1,6 linkages in pullulan and release maltotriose are called pullulanases although pullulan itself may not be the natural substrate.

1: Further evidence for the mandatory nature of polysaccharide debranching for the aggregation of semicrystalline starch and for overlapping functions of debranching enzymes in Arabidopsis leaves. Wattebled F, Planchot V, Dong Y, Szydlowski N, Pontoire B, Devin A, Ball S, D'Hulst C; Plant Physiol. 2008;148:1309-1323. PMID:18815382