Predicted to enable dol-P-Man:Man(5)GlcNAc(2)-PP-Dol alpha-1,3-mannosyltransferase activity. Predicted to be involved in protein glycosylation. Predicted to be located in endoplasmic reticulum membrane. Predicted to be active in endoplasmic reticulum. Is expressed in several structures, including alimentary system; genitourinary system; integumental system; nervous system; and retina. Human ortholog(s) of this gene implicated in congenital disorder of glycosylation Id. Orthologous to human ALG3 (ALG3 alpha-1,3- mannosyltransferase). [provided by Alliance of Genome Resources, Apr 2022]