Reaction catalyzed by xyloglucan 6-xylosyltransferase (2.4.2.39)

		+			=			+
	UDP-D-xylose	+		Glcbeta(1-4)(Xylalpha(1-6))Glcbeta(1-4)(Xylalpha(1-6))Glcbeta-R	=		UDP	+		Xylalpha(1-6)Glcbeta(1-4)(Xylalpha(1-6))Glcbeta(1-4)(Xylalpha(1-6))Glcbeta-R