Antiporter that transports inorganic anions (sulfate, sulfite, thiosulfate and phosphate) and, to a lesser extent, a variety of dicarboxylates (e.g. malonate, malate and citramalate) and, even more so, aspartate. The sulfate/sulfate exchange is much higher than the phosphate/phosphate and malate/malate exchanges. The transport affinities is higher for sulfate and thiosulfate than for any other substrate. May catalyze the export of sulfite and thiosulfate (the hydrogen sulfide degradation products) from the mitochondria, thereby modulating the level of the hydrogen sulfide. Also may mediate a very low unidirectional transport of sulfate, phosphate and (S)-malate.
Subcellular locations: Mitochondrion inner membrane