ferredoxin—nitrite reductase

{{Short description|Class of enzymes}}

{{infobox enzyme

| Name = ferredoxin—nitrite reductase

| EC_number = 1.7.7.1

| CAS_number = 37256-44-3

| GO_code = 0048307

| image =

| width =

| caption =

}}

In enzymology, a ferredoxin—nitrite reductase ({{EC number|1.7.7.1}}) is an enzyme that catalyzes the chemical reaction

:NH₃ + 2 H₂O + 6 oxidized ferredoxin $\backslash rightleftharpoons$ nitrite + 6 reduced ferredoxin + 7 H⁺

The 3 substrates of this enzyme are NH₃, H₂O, and oxidized ferredoxin, whereas its 3 products are nitrite, reduced ferredoxin, and H⁺.

This enzyme belongs to the family of oxidoreductases, specifically those acting on other nitrogenous compounds as donors with an iron-sulfur protein as acceptor. The systematic name of this enzyme class is ammonia:ferredoxin oxidoreductase. This enzyme participates in nitrogen metabolism and nitrogen assimilation. It has 3 cofactors: iron, Siroheme, and Iron-sulfur.

This enzyme can use many different isoforms of ferredoxin. In photosynthesizing tissues, it uses ferredoxin that is reduced by PSI and in the root it uses a form of ferredoxin (FdIII) that has a less negative midpoint potential and can be reduced easily by NADPH.{{Cite journal | last1 = Hanke | first1 = G. T. | last2 = Kimata-Ariga | first2 = Y. | last3 = Taniguchi | first3 = I. | last4 = Hase | first4 = T. | title = A Post Genomic Characterization of Arabidopsis Ferredoxins | doi = 10.1104/pp.103.032755 | journal = Plant Physiology | volume = 134 | issue = 1 | pages = 255–264 | year = 2004 | pmid = 14684843| pmc =316305 }}