The SUOX gene maps to chromosome 12q13.2, where it encodes a mitochondrial enzyme called sulfite oxidase. This protein comprises of 545 amino acids protein and weighs about 60 kDa. The enzyme is a metalloenzyme localized to the intermembrane space of mitochondria that uses a molybdopterin cofactor and a heme group to oxidize sulfite to sulfate, the final step in the degradation of sulfur-containing amino acids and environmental sulfites.