N-acetylglucosamine 6-sulfatase (GNS) hydrolyses 6-sulfate groups of the N-acetyl-D-glucosamine 6-sulfate units of keratan sulfate Authored: Jassal, B, 2011-10-05 EC Number: 3.1.6.14 Edited: Jassal, B, 2011-10-05 N-acetylglucosamine 6-sulfatase (GNS) is a lysosomal enzyme which degrades glycosaminoglycans such as heparan sulfate and keratan sulfate. GNS shows strong sequence similarity to other sulphatases such as the family of arylsulfatases and the conversion to 3-oxo-alanine (formylglycine, FGly) of a cysteine residue is critical for catalytic activity, based on this similarity (Robertson et al. 1992, Robertson et al. 1988). Defects in GNS are the cause of mucopolysaccharidosis type IIID (MPSIIID, MIM:252940), also called Sanfilippo D syndrome (Valstar et al. 2010). Pubmed1463457 Pubmed20232353 Pubmed3196333 Reactome Database ID Release 431638032 Reactome, http://www.reactome.org ReactomeREACT_120828 Reviewed: D'Eustachio, P, 2012-03-28