A molybdenum cofactor is a biochemical cofactor that contains molybdenum.
Examples include:
- Molybdopterin (or, strictly speaking, the molybdopterin-molybdenum-complex), the organophosphate-dithiolate ligand that binds molybdenum and tungsten in most molybdenum- (except nitrogenases) and all tungsten-containing proteins
- FeMoco, a metal cluster that contains Fe, Mo, and S that is found in some nitrogenases