Why Is Soxcd Not Oxidized Free Sulfite

In previous studies, according to the evidence of biochemistry and structural analysis, it was proved that SoxCD was a sulfane dehydrogenase, SoxCD cannot oxidized free sulfite, it can only use SoxYZ bound thiosulfate as substrate, catalyzed thiosulfate performed a 6-electron oxidation reaction to produce sulfate (Zander et al., 2011). In autotrophic bacteria, the knockout strain of SoxCD still has the function of oxidized thiosulfate (Friedrich et al., 2000), suggested that there may be an alternative system for SoxCD. For example, SOX system in the Allochromatium vinosum was similar to the P. pantotrophus GB17 except that the former did not have SoxCD. In addition, there was a SoxL enzyme which was a sulfur transferase located on the downstream