catalytic activity:L-cysteine + O(2) = 3-sulfinoalanine.,cofactor:Binds 1 iron ion per subunit. Zinc to a much lesser extent.,cofactor:IRON; NAD(P)H.,function:Initiates several important metabolic pathways related to pyruvate and several sulfurate compounds including sulfate, hypotaurine and taurine. Critical regulator of cellular cysteine concentrations. Has an important role in maintaining the hepatic concentation of intracellular free cysteine within a proper narrow range.,induction:In hepatoblastoma HepG2 cells, down-regulated by phorbol 12-myristate 13-acetate.,pathway:Organosulfur biosynthesis; taurine biosynthesis; hypotaurine from L-cysteine: step 1/2.,PTM:The thioether cross-link between Cys-93 and Tyr-157 plays a structural role through stabilizing the Fe(2+) ion, and prevents the production of highly damaging free hydroxyl radicals by holding the oxygen radical via hydroxyl hydrogen.,similarity:Belongs to the cysteine dioxygenase family.,subunit:Monomer.,tissue specificity:Highly expressed in liver and placenta. Low expression in heart, brain and pancreas. Also detected in hepatoblastoma HepG2 cells.,