Dehydrodolichyl diphosphate (dedol-PP) synthase catalyzes cis-prenyl chain elongation to produce the polyprenyl backbone of dolichol, a glycosyl carrier lipid required for the biosynthesis of several classes of glycoproteins.Dehydrodolichyl diphosphate (dedol-PP) synthase catalyzes cis-prenyl chain elongation to produce the polyprenyl backbone of dolichol, a glycosyl carrier lipid required for the biosynthesis of several classes of glycoproteins.[supplied by OMIM].