Catalyzes the transfer of sulfate to the C2-position of selected hexuronic acid residues within the maturing heparan sulfate (HS). Involved in cell adhesion and guidance by specifically modifying proteoglycans in the extracellular matrix and on the cell surface that are essential for axon migrations. Homotrimer. Present in the hypodermis, muscle, distal tip cells (DTCs) and in neurons (at protein level). Worms are viable but display axonal and cellular guidance defects in specific neuron classes. Belongs to the sulfotransferase 3 family.