Predicted to enable magnesium ion binding activity; manganese ion binding activity; and xylosyl alpha-1,3-xylosyltransferase activity. Predicted to be involved in O-glycan processing. Predicted to be integral component of endoplasmic reticulum membrane. Orthologous to human XXYLT1 (xyloside xylosyltransferase 1). [provided by Alliance of Genome Resources, Apr 2022]