Sulfide dehydrogenase is identical with the SoxB protein of the thiosulfate‐oxidizing enzyme system of Paracoccus denitrificans GB17

Abstract
Thiosulfate induced cells of Paracoccus denitrificans GB17 oxidize thiosulfate and sulfide to sulfate. A mutant carrying a Tn5-mob insertion in the soxB gene is unable to oxidize thiosulfate or sulfide suggesting a linkage of both activities. To test this assumption we have separated the components of the thiosulfate-oxidizing enzyme system of the wild-type by ion exchange chromatography. The SoxB protein coeluted with a highly active sulfide dehydrogenase. Analysis by polyacrylamide gel electrophoresis revealed one major protein of M r 32k. Thus, the SoxB protein appeared to be identical with sulfide dehydrogenase.