A mammalian homolog of the bacterial monomeric sarcosine oxidases maps to mouse chromosome 11, close to Cryba1.

We have cloned a cDNA from a mouse gene, Pso (peroxisomal sarcosine oxidase). Pso appears to encode a homolog of the single-subunit (40 kDa) bacterial sarcosine oxidases. The mouse Pso gene product would contain a peroxisomal localization sequence, like that of the recently reported rabbit enzyme, Mouse Pso lies between 20 and 50 kb upstream of the promoter of the Sez6 gene, close to Crybal on chromosome 11. Pso is expressed very strongly and specifically in liver and kidney. The gene appears to be present widely in eutherian mammals.