Ferredoxin—NADP(+) reductase

In enzymology, a ferredoxin-NADP⁺ reductase (EC 1.18.1.2) abbreviated FNR, is an enzyme that catalyzes the chemical reaction

2 reduced ferredoxin + NADP⁺ + H⁺ ${\displaystyle \rightleftharpoons }$ 2 oxidized ferredoxin + NADPH

The 3 substrates of this enzyme are reduced ferredoxin, NADP⁺, and H⁺, whereas its two products are oxidized ferredoxin and NADPH. It has a flavin cofactor, FAD.

This enzyme belongs to the family of oxidoreductases, that use iron-sulfur proteins as electron donors and NAD⁺ or NADP⁺ as electron acceptors.

This enzyme participates in photosynthesis. FNR provides a major source of NADPH for photosynthetic organisms.