This enzyme belongs to the family of oxidoreductases, specifically those acting on a sulfur group of donors with a cytochrome as acceptor. The systematic name of this enzyme class is thiosulfate:ferricytochrome-c oxidoreductase. Other names in common use include tetrathionate synthase, thiosulfate oxidase, thiosulfate-oxidizing enzyme, and thiosulfate-acceptor oxidoreductase.
Lu, W-P and Kelly DP (1988). "Cellular location and partial purification of the 'thiosulphate-oxidizing enzyme' and 'trithionate hydrolase' from Thiobacillus tepidarius". J. Gen. Microbiol.134: 877–885. doi:10.1099/00221287-134-4-877.