EC - Glutamate synthase (NADPH)

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IntEnz Enzyme Nomenclature


Accepted name:
glutamate synthase (NADPH)
Other names:
L-glutamate synthase
L-glutamate synthetase
L-glutamine:2-oxoglutarate aminotransferase, NADPH oxidizing
NADPH-dependent glutamate synthase
NADPH-glutamate synthase
NADPH-linked glutamate synthase
glutamate (reduced nicotinamide adenine dinucleotide phosphate) synthase
glutamate synthetase (NADP)
glutamine amide-2-oxoglutarate aminotransferase (oxidoreductase, NADP)
glutamine-ketoglutaric aminotransferase
Systematic name:
L-glutamate:NADP+ oxidoreductase (transaminating)




Binds FMN, FAD, 2 [4Fe-4S] clusters and 1 [3Fe-4S] cluster. The reaction takes place in the opposite direction. The protein is composed of two subunits, α and β. The α subunit is composed of two domains, one hydrolysing L-glutamine to NH3 and L-glutamate (cf. EC, glutaminase), the other combining the produced NH3 with 2-oxoglutarate to produce a second molecule of L-glutamate (cf. EC, glutamate dehydrogenase [NADP+]). The β subunit transfers electrons from the cosubstrate. The NH3 is channeled through a 31 Å channel in the active protein. In the absence of the β subunit, coupling between the two domains of the α subunit is compromised and some ammonium can be produced. In the intact αβ complex, ammonia production only takes place as part of the overall reaction.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Protein domains and families: PROSITE:PDOC00406
Structural data: CSA , EC2PDB
Gene Ontology: GO:0004355
CAS Registry Number: 37213-53-9
UniProtKB/Swiss-Prot: (18) [show] [UniProt]


  1. Miller, R.E. and Stadtman, E.R.
    Glutamate synthase from Escherichia coli. An iron-sulfide flavoprotein.
    J. Biol. Chem. 247 : 7407-7419 (1972). [PMID: 4565085]
  2. Tempest, D.W., Meers, J.L. and Brown, C.M.
    Synthesis of glutamate in Aerobacter aerogenes by a hitherto unknown route.
    Biochem. J. 117 : 405-407 (1970). [PMID: 5420057]
  3. Vanoni, M. A., Curti, B.
    Glutamate synthase: a complex iron-sulfur flavoprotein.
    Cell. Mol. Life Sci. 55 : 617-638 (1999). [PMID: 10357231]
  4. Ravasio, S., Curti, B., Vanoni, M. A.
    Determination of the midpoint potential of the FAD and FMN flavin cofactors and of the 3Fe-4S cluster of glutamate synthase.
    Biochemistry 40 : 5533-5541 (2001). [PMID: 11331018]

[EC created 1972 as EC, transferred 1976 to EC, modified 2001, modified 2010]