Background：Sulfotransferase that utilizes 3'-phospho-5'-adenylyl sulfate(PAPS) as sulfonate donor to catalyze the transfer of sulfate to position 6 of galactose(Gal) residues of keratan. Has a preference for sulfating keratan sulfate, but it also transfers sulfate to the unsulfated polymer. The sulfotransferase activity on sialyl LacNAc structures is much higher than the corresponding desialylated substrate, and only internal Gal residues are sulfated. May function in the sulfation of sialyl N-acetyllactosamine oligosaccharide chains attached to glycoproteins. Participates in biosynthesis of selectin ligands. Selectin ligands are present in high endothelial cells(HEVs) and play a central role in lymphocyte homing at sites of inflammation.
