Lysosomal enzyme involved in the degradation pathway of dermatan sulfate and heparan sulfate. Hydrolysis of the 2-sulfate groups of the L-iduronate 2-sulfate units of dermatan sulfate, heparan sulfate and heparin. Binds 1 Ca(2+) ion per subunit. Monomer. The 58-kDa mature form is composed of two chains resulting from proteolitic processing, the 42-kDa chain and the 14-kDa chain that remain stably associated and form the 58-kDa intermediate form which is enzymatically active. Found to be expressed in alpha and beta pancreatic cells. By glucose, in a dose dependent manner. Synthesized as a 75-kDa precursor form in the endoplasmic reticulum (ER), and then processed by proteolytic cleavage through various intermediates to yield a 55-kDa mature form, with the release of an 18 kDa polypeptide. The conversion to 3-oxoalanine (also known as C-formylglycine, FGly), of a serine or cysteine residue in prokaryotes and of a cysteine residue in eukaryotes, is critical for catalytic activity. Belongs to the sulfatase family.