Glutamate synthase (NADPH)

glutamate synthase (NADPH)
Glutamate synthase dodekamer, Azospirillum br.
Identifiers
EC no.	1.4.1.13
CAS no.	37213-53-9
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

In enzymology, a glutamate synthase (NADPH) (EC 1.4.1.13) is an enzyme that catalyzes the chemical reaction

L-glutamine + 2-oxoglutarate + NADPH + H^+ ${\displaystyle \rightleftharpoons }$ 2 L-glutamate + NADP^+

Thus, the four substrates of this enzyme are L-glutamine, 2-oxoglutarate (α-ketoglutarate), NADPH, and H^+, whereas the two products are L-glutamate and NADP^+.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH2 group of donors with NAD+ or NADP+ as acceptor. This enzyme participates in glutamate metabolism and nitrogen metabolism. It has 5 cofactors: FAD, Iron, FMN, Sulfur, and Iron-sulfur.

It occurs in bacteria and plants but not animals, and is important as it provides glutamate for the glutamine synthetase reaction.[1][2]

Nomenclature

The systematic name of this enzyme class is L-glutamate:NADP+ oxidoreductase (transaminating). Other names in common use include:

• glutamate (reduced nicotinamide adenine dinucleotide phosphate), synthase,
• glutamate synthase (NADPH),
• glutamate synthetase (NADP),
• glutamine amide-2-oxoglutarate aminotransferase (oxidoreductase, NADP),
• glutamine-ketoglutaric aminotransferase,
• L-glutamate synthase,
• L-glutamate synthetase,
• L-glutamine:2-oxoglutarate aminotransferase, NADPH oxidizing,
• NADPH-dependent glutamate synthase,
• NADPH-glutamate synthase, and
• NADPH-linked glutamate synthase.

Structural studies

As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code 1EA0.

See also

• Glutamate synthase (NADH)
• Glutamate synthase (ferredoxin)

References

1. Temple SJ, Vance CP, Gantt JS (1998). "Glutamate synthase and nitrogen assimilation". Trends in Plant Science. 3 (2): 51–56. Bibcode:1998TPS.....3...51T. doi:10.1016/S1360-1385(97)01159-X.
2. Vanoni MA, Curti B (May 2008). "Structure-function studies of glutamate synthases: a class of self-regulated iron-sulfur flavoenzymes essential for nitrogen assimilation". IUBMB Life. 60 (5): 287–300. doi:10.1002/iub.52. PMID 18421771. S2CID 33617681.

Further reading

• Miller RE, Stadtman ER (1972). "Glutamate synthase from Escherichia coli. An iron-sulfide flavoprotein". J. Biol. Chem. 247 (22): 7407–19. doi:10.1016/S0021-9258(19)44642-5. PMID 4565085.
• Tempest DW, Meers JL, Brown CM (1970). "Synthesis of glutamate in Aerobacter aerogenes by a hitherto unknown route". Biochem. J. 117 (2): 405–7. doi:10.1042/bj1170405. PMC 1178874. PMID 5420057.