a di-trans,poly-cis-dolichyl D-xylosyl phosphate  + L-seryl-[protein] <=> 3-O-(beta-D-xylosyl)-L-seryl-[protein] + a di-trans,poly-cis-dolichyl phosphate + H(+)
a di-trans,poly-cis-dolichyl d-xylosyl phosphate  + l-seryl-[protein] <=> 3-o-(beta-d-xylosyl)-l-seryl-[protein] + a di-trans,poly-cis-dolichyl phosphate + h(+)
a di-trans,poly-cis-dolichyl D-xylosyl phosphate  + L-seryl-[protein] <=> 3-O-(beta-D-xylosyl)-L-seryl-[protein] + a di-trans,poly-cis-dolichyl phosphate + H(+)
a di-trans,poly-cis-dolichyl d-xylosyl phosphate  + l-seryl-[protein] <=> 3-o-(beta-d-xylosyl)-l-seryl-[protein] + a di-trans,poly-cis-dolichyl phosphate + h(+)