Enables molybdenum ion binding activity; molybdopterin cofactor binding activity; and oxidoreductase activity, acting on other nitrogenous compounds as donors. Contributes to nitrite reductase (NO-forming) activity. Involved in cellular detoxification of nitrogen compound; nitrate metabolic process; and nitric oxide biosynthetic process. Located in mitochondrion. Part of nitric-oxide synthase complex. [provided by Alliance of Genome Resources, Apr 2022]