This gene encodes an enzyme which catalyzes the translocation of the Man(5)GlcNAc (2)-PP-Dol intermediate from the cytoplasmic to the luminal side of the endoplasmic reticulum membrane in the pathway for the N-glycosylation of proteins. Mutations in this gene are associated with congenital disorder of glycosylation type In.[provided by RefSeq, Dec 2008].