Catalyzes the oxidation of hydrogen sulfide with the help of a quinone, such as ubiquinone-10, giving rise to thiosulfate and ultimately to sulfane (molecular sulfur) atoms. Requires an additional electron acceptor; can use sulfite, sulfide or cyanide (in vitro) (PubMed:22852582). It is believed the in vivo electron acceptor is glutathione (PubMed:25225291, PubMed:29715001).