Motherway, MO,Fitzgerald, GF,Neirynck, S,Ryan, S,Steidler, L,van Sinderen, D;

2008

August

Applied and Environmental Microbiology

Characterization of ApuB, an extracellular type II amylopullulanase from Bifidobacterium breve UCC2003

Validated

()

COMPLETE GENOME SEQUENCE DIFFERENT ACTIVE-SITES LACTOCOCCUS-LACTIS LACTOBACILLUS-ACIDOPHILUS ALKALINE AMYLOPULLULANASE SUBSTRATE-SPECIFICITY PYROCOCCUS-FURIOSUS GENE-EXPRESSION ALPHA-AMYLASE IDENTIFICATION

74

6271

6279

The apuB gene of Bifidobacterium breve UCC2003 was shown to encode an extracellular amylopullulanase. ApuB is composed of a distinct N-terminally located alpha-amylase-containing domain which hydrolyzes alpha-1,4-glucosidic linkages in starch and related polysaccharides and a C-terminally located pullulanase-containing domain which hydrolyzes alpha-1,6 linkages in pullulan, allowing the classification of this enzyme as a bifunctional class II pullulanase. A knockout mutation of the apuB gene in B. breve UCC2003 rendered the resulting mutant incapable of growth in medium containing starch, amylopectin, glycogen, or pullulan as the sole carbon and energy source, confirming the crucial physiological role of this gene in starch metabolism.

DOI 10.1128/AEM.01169-08