Cleaves the distal alpha 1,2-linked glucose residue from the Glc(3)Man(9)GlcNAc(2) oligosaccharide precursor in a highly specific manner.
Glycan metabolism; N-glycan degradation.
Involvement in disease
Defects in MOGS are the cause of type IIb congenital disorder of glycosylation (CDGIIb) [MIM:606056]; also known as glucosidase I deficiency. CDGIIb is characterized by marked generalized hypotonia and hypomotility of the neonate, dysmorphic features, including a prominent occiput, short palpebral fissures, retrognathia, high arched palate, generalized edema, and hypoplastic genitalia. Symptoms of the infant included hepatomegaly, hypoventilation, feeding problems and seizures. The clinical course was progressive and the infant did not survive more than a few months.