Sulfotransferase that utilizes 3'-phospho-5'-adenylyl sulfate (PAPS) to catalyze the transfer of a sulfo group to position 3 of glucosamine residues in heparan ( ). Catalyzes the rate limiting step in the biosynthesis of heparan sulfate (HSact) (, ). This modification is a crucial step in the biosynthesis of anticoagulant heparan sulfate as it completes the structure of the antithrombin pentasaccharide binding site (, ).
Subcellular locations: Golgi apparatus lumen
Highly expressed in the brain and kidney and weakly expressed in the heart, lung and placenta.