Definition: An iron-sulfur and MOLYBDENUM containing FLAVOPROTEIN that catalyzes the oxidation of nitrite to nitrate. This enzyme can use either NAD or NADP as cofactors. It is a key enzyme that is involved in the first step of nitrate assimilation in PLANTS; FUNGI; and BACTERIA. This enzyme was formerly classified as EC 126.96.36.199.
do not confuse with NITRATE REDUCTASE (NADPH) or NITRATE REDUCTASE (NADH) or NITRITE REDUCTASE (NAD(P)H)