6-O-sulfation enzyme which catalyzes the transfer of sulfate from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to position 6 of the N-sulfoglucosamine residue (GlcNS) of heparan sulfate. 3'-phosphoadenylyl sulfate + alpha-D-glucosaminyl-[heparan sulfate](n) = 6-sulfo-alpha-D-glucosaminyl-[heparan sulfate](n) + adenosine 3',5'-bisphosphate + H(+) During early somitogenesis, first expressed in floor plate and somites. During mid-somitogenesis, expressed strongly in somites and more weakly in eye and hindbrain. During late somitogenesis, expressed in eye, hindbrain and posterior somites. At 24 hours post-fertilization (hpf), expressed in lens, forebrain, hindbrain, otic vesicle, anterior spinal cord neurons and posterior somites. At 36 hpf, expressed in the retinal ciliary marginal zone, brain, pancreas and weakly in pectoral fin. At 48 hpf, expressed in the retinal ciliary marginal zone, retinal ganglion cells, rhombomeres, otic vesicle and weakly in pectoral fin. Expressed both maternally and zygotically. Expression is lost before gastrulation and begins again during early somitogenesis. Belongs to the sulfotransferase 6 family.