an aryl sulfate + H2O = a phenol + H(+) + sulfate Binds 1 Ca(2+) ion per subunit. Expression is confined to aboral ectoderm cells and their precursors. Low levels are found at mesenchyme blastula stage (24 hours), levels increase by late gastrula stage and are maintained at pluteus stage. 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.