Predicted to enable GDP-Man:Man3GlcNAc2-PP-Dol alpha-1,2-mannosyltransferase activity. Predicted to act upstream of or within dolichol-linked oligosaccharide biosynthetic process. Predicted to be located in endoplasmic reticulum and membrane. Predicted to be active in endoplasmic reticulum membrane. Human ortholog(s) of this gene implicated in congenital disorder of glycosylation Ip. Orthologous to human ALG11 (ALG11 alpha-1,2-mannosyltransferase).