Exchange of oxygen with sulfur in MoCo Authored: Stephan, R, 2010-09-07 Edited: Jassal, B, 2010-09-08 Pubmed11302742 Reactome Database ID Release 43947499 Reactome, http://www.reactome.org ReactomeREACT_25122 Reviewed: D'Eustachio, P, 2010-11-05 While the biosynthesis of the molybdenum cofactor for sulfite oxidase is finished after molybdenum ion insertion, human xanthine oxidase and aldehyde oxidase will only show activity with this cofactor when one of the oxygens bound to molybdenum is replaced with sulfur. The exchange is catalyzed by the MOCOS cysteine desulfurase (Ichida et al, 2001).