PAP2_like proteins, dolichyldiphosphatase subfamily. Dolichyldiphosphatase is a membrane-associated protein located in the endoplasmic reticulum and hydrolyzes dolichyl pyrophosphate, as well as dolichylmonophosphate at a low rate. The enzyme is necessary for maintaining proper levels of dolichol-linked oligosaccharides and protein N-glycosylation, and might play a role in re-utilization of the glycosyl carrier lipid for additional rounds of lipid intermediate biosynthesis after its release during protein N-glycosylation reactions.