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(+) In early somitogenesis, expressed in presumptive forebrain and midbrain, tail bud and Kupffer's vesicle. During mid-somitogenesis, ubiquitous expression which is strongest in the somites and eye. During late somitogenesis, predominantly expressed in eye, hindbrain and ventral somites. At 24 hours post-fertilization (hpf), restricted to lens and neural retina, brain, otic vesicle and somites. At 36 hpf, brain expression is restricted to telencephalon. At 48 hpf, restricted to telencephalon and pectoral fin. Expressed both maternally and zygotically. Belongs to the sulfotransferase 6 family.