FIG. 2.

Schematic overview of key genes/enzymes putatively associated with sulfur-compound oxidation in T. denitrificans. Genes in parenthesis have been shown to be lesser expressed paralogs (this study). The biochemical roles of a number of gene products represented in this figure have not been experimentally demonstrated in T. denitrificans and are uncertain. Sulfide:quinone oxidoreductase is not proposed to catalyze the direct oxidation of sulfide to sulfite but rather may participate in an indirect pathway (20). The arrow between thiosulfate and sulfate (right side) represents the possibility that SoxB catalyzes a sulfate thiohydrolase reaction (28) in T. denitrificans. APAT, APS:phosphate adenylyltransferase.