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 somitogenesis, first expressed in polster and presumptive forebrain. During mid-somitogenesis, expressed in eye, hindbrain and anterior spinal cord. During late somitogenesis, strong expression in eye and hindbrain, decreased levels in midbrain and anterior spinal cord. At 24 hours post-fertilization (hpf), expressed in neural retina and lens, brain and anterior spinal cord. At 36 hpf, retinal expression is confined to the ciliary marginal zone and there is strong expression in tectum, rhombomeres and otic vesicle. At 48 hpf, expressed in retinal ganglion cells and in tectum, rhombomeres and pectoral fin. Not detected in the vasculature during embryogenesis. Expressed both maternally and zygotically. Expression is lost before gastrulation and begins again during somitogenesis. Belongs to the sulfotransferase 6 family.