Members of this protein resemble conventional xanthine dehydrogenase enzymes, which depend on molybdenum cofactor - molybdopterin bound to molybdate with two sulfur atoms as ligands. But all members of this family occur in species that contain markers for the biosynthesis of enzymes with a selenium-containing form of molybdenum cofactor. The member of this family from Enterococcus faecalis has been shown to act as a xanthine dehydrogenenase, and its activity if dependent on SelD (selenophosphate synthase), selenium, and molybdenum. [Purines, pyrimidines, nucleosides, and nucleotides, Other]
Jiyao W et al.(2023). "The conserved domain database in 2023.",