A second glucose is removed from the N-linked glycan. The removal of an alpha1,3 glucose moiety is catalyzed by glucosidase II, a complex composed of an alpha subunit (GANAB) with catalytic activity and a beta subunit (GLU2B; PRKCSH), probably with regulatory and recruitment function (Pelletier MF et al, 2000). GANAB can exist in two different isoforms, but both are able to catalyze both of the reactions catalyzed by glucosidase II (Pelletier MF et al, 2000). Defects in PRKCSH are a cause of polycystic liver disease (PCLD).
glucan 1,3-alpha-glucosidase activity of glucosidase II [endoplasmic reticulum lumen]