glutamate synthase (ferredoxin);
ferredoxin-dependent glutamate synthase;
ferredoxin-glutamate synthase;
glutamate synthase (ferredoxin-dependent)

Oxidoreductases;
Acting on the CH-NH2 group of donors;
With an iron-sulfur protein as acceptor

L-glutamate:ferredoxin oxidoreductase (transaminating)

2 L-glutamate + 2 oxidized ferredoxin = L-glutamine + 2-oxoglutarate + 2 reduced ferredoxin + 2 H+ (overall reaction) [RN:R00021];
(1a) L-glutamate + NH3 = L-glutamine + H2O [RN:R00256];
(1b) L-glutamate + 2 oxidized ferredoxin + H2O = NH3 + 2-oxoglutarate + 2 reduced ferredoxin + 2 H+ [RN:R10086]

R00021 R00256 R10086

L-glutamate [CPD:C00025];
oxidized ferredoxin [CPD:C00139];
NH3 [CPD:C00014];
H2O [CPD:C00001]

Binds a [3Fe-4S] cluster as well as FAD and FMN. The protein is composed of two domains, one hydrolysing L-glutamine to NH3 and L-glutamate (cf. EC 3.5.1.2, glutaminase), the other combining the produced NH3 with 2-oxoglutarate to produce a second molecule of L-glutamate. The NH3 is channeled through a 24 A channel in the active protein. No hydrolysis of glutamine takes place without ferredoxin and 2-oxoglutarate being bound to the protein [5,6].

1

Galvan, F., Marquez, A.J. and Vega, J.M.

Purification and molecular properties of ferredoxin-glutamate synthase from Chlamydomonas reinhardii.

Planta 162 (1984) 180-187.

2  [PMID:4423889]

Lea PJ, Miflin BJ.

Alternative route for nitrogen assimilation in higher plants.

Nature. 251 (1974) 614-6.

3  [PMID:12069605]

Ravasio S, Dossena L, Martin-Figueroa E, Florencio FJ, Mattevi A, Morandi P, Curti B, Vanoni MA

Properties of the recombinant ferredoxin-dependent glutamate synthase of Synechocystis PCC6803. Comparison with the Azospirillum brasilense NADPH-dependent enzyme and its isolated alpha subunit.

Biochemistry. 41 (2002) 8120-33.

4  [PMID:10898944]

Navarro F, Martin-Figueroa E, Candau P, Florencio FJ

Ferredoxin-dependent iron-sulfur flavoprotein glutamate synthase (GlsF) from the  Cyanobacterium synechocystis sp. PCC 6803: expression and assembly in Escherichia coli.

Arch. Biochem. Biophys. 379 (2000) 267-76.

5  [PMID:11967268]

van den Heuvel RH, Ferrari D, Bossi RT, Ravasio S, Curti B, Vanoni MA, Florencio FJ, Mattevi A

Structural studies on the synchronization of catalytic centers in glutamate synthase.

J. Biol. Chem. 277 (2002) 24579-83.

6  [PMID:12818206]

van den Heuvel RH, Svergun DI, Petoukhov MV, Coda A, Curti B, Ravasio S, Vanoni MA, Mattevi A

The active conformation of glutamate synthase and its binding to ferredoxin.

J. Mol. Biol. 330 (2003) 113-28.