View source for Biology: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 [[Biology:Enzymology|enzymology]], a '''ferredoxin—nitrite reductase''' ({{EC number|1.7.7.1}}) is an [[Biology:Enzyme|enzyme]] that [[Chemistry:Catalysis|catalyzes]] the [[Chemistry:Chemical reaction|chemical reaction]]

:NH<sub>3</sub> + 2 H<sub>2</sub>O + 6 oxidized [[Biology:Ferredoxin|ferredoxin]] <math>\rightleftharpoons</math> nitrite + 6 reduced ferredoxin + 7 H<sup>+</sup>

The 3 [[Biology:Substrate (biochemistry)|substrates]] of this enzyme are [[Chemistry:Ammonia|NH<sub>3</sub>]], [[Chemistry:Water|H<sub>2</sub>O]], and oxidized ferredoxin, whereas its 3 [[Chemistry:Product|products]] are [[Chemistry:Nitrite|nitrite]], reduced ferredoxin, and [[Physics:Hydrogen ion|H<sup>+</sup>]].

This enzyme belongs to the family of [[Biology:Oxidoreductase|oxidoreductase]]s, specifically those acting on other nitrogenous compounds as donors with an iron-sulfur protein as acceptor.  The [[Biology:List of enzymes|systematic name]] of this enzyme class is '''ammonia:ferredoxin oxidoreductase'''. This enzyme participates in nitrogen metabolism and [[Biology:Nitrogen assimilation|nitrogen assimilation]].  It has 3 [[Biology:Cofactor (biochemistry)|cofactors]]: [[Chemistry:Iron|iron]], [[Biology:Siroheme|Siroheme]],  and Iron-sulfur.

This enzyme can use many different isoforms of ferredoxin. In photosynthesizing tissues, it uses ferredoxin that is reduced by [[Biology:Photosystem I|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.<ref name=Hanke2003>{{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 }}</ref>

==Structural studies==

As of late 2007, 3 [[Biology:Tertiary structure|structures]] have been solved for this class of enzymes, with [[Biology:Protein Data Bank|PDB]] accession codes {{PDB link|1ZJ8}}, {{PDB link|1ZJ9}}, and {{PDB link|2AKJ}}.

==References==
{{reflist|1}}

== Literature ==
{{refbegin}}
* {{cite journal |vauthors=Joy KW, Hageman RH | year = 1966 | title = The purification and properties of nitrite reductase from higher plants, and its dependence on ferredoxin | journal = Biochem. J.  | volume = 100 | pages = 263&ndash;73  | pmid = 4381617 | issue = 1 | doi = 10.1042/bj1000263 | pmc = 1265119 }}
* {{cite journal |vauthors=Ramirez JM, Del Campo FF, Paneque A, Losada M | year = 1966 | title = Ferredoxin-nitrite reductase from spinach | journal = Biochim. Biophys. Acta  | volume = 118 | pages = 58&ndash;71  | pmid = 5954064 | issue = 1 | doi=10.1016/s0926-6593(66)80144-3}}
* {{cite journal |vauthors=Zumft WG, Paneque A, Aparicio PJ, Losada M | year = 1969 | title = Mechanism of nitrate reduction in Chlorella | journal = Biochem. Biophys. Res. Commun.  | volume = 36 | pages = 980&ndash;6  | pmid = 4390523 | doi = 10.1016/0006-291X(69)90300-3 | issue = 6 }}
{{refend}}

{{Nitrogenous donor oxidoreductases}}
{{Enzymes}}

{{DEFAULTSORT:Ferredoxin-nitrite reductase}}
[[Category:EC 1.7.7]]
[[Category:Iron enzymes]]
[[Category:Iron-sulfur enzymes]]
[[Category:Enzymes of known structure]]



{{Sourceattribution|Ferredoxin—nitrite reductase}}