InterPro: IPR011838 Pullulanase, extracellular

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. In contrast, a glycogen debranching enzyme such GlgX, homologous to this family, can release glucose at alpha,1-6 linkages from glycogen first subjected to limit degradation by phosphorylase. Characterised members of this family include a surface-located pullulanase from Streptococcus pneumoniae [1] and an extracellular bifunctional amylase/pullulanase with C-terminal pullulanase activity [2].