Molybdenum Cofactor Sulfurase (MOCOS)

MOCOS sulfurates the molybdenum cofactor of xanthine dehydrogenase (XDH) and aldehyde oxidase (AOX1), which is required for their enzymatic activities.

By searching an EST database for sequences similar to MOCOS orthologs in Aspergillus and Drosophila, followed by PCR of a liver cDNA library and database analysis, Ichida et al. (2001) obtained full-length human MOCOS, which they called HMCS. The deduced 888-amino acid protein contains a pyridoxal phosphate-binding site motif and has characteristics of an NifS (NFS1)-like protein. MOCOS shares about 30% identity with the Aspergillus and Drosophila proteins and about 80% identity with bovine Mocos.