Cysteine dioxygenase involved in sulfite formation from cysteine. Plays an important role in filamentous growth and virulence. L-cysteine + O2 = 3-sulfino-L-alanine + H(+) Binds 1 Fe cation per subunit. Expression is under the control of the ZCF2 transcription factor and is regulated upon white-opaque switching. Transcription is also up-regulated in both intermediate and mature biofilms. The thioether cross-link between Cys-157 and Tyr-221 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. Displays reduced hyphae formation in the presence of cysteine and leads to attenuated virulence. Belongs to the cysteine dioxygenase family.