GO:0050694:   galactose 3-O-sulfotransferase activity
Catalysis of the reaction: N-acetyllactosamine + 3"-phosphoadenosine 5"-phosphosulfate = 3-sulfo-N-acetyllactosamine + adenosine 3",5"-bisphosphate. N-acetyllactosamine residues are found in a number of different carbohydrate types. N-acetyllactosamine can also be written as Gal-beta-(1,4)-GlcNAc.