Glutamate synthase (NADPH)
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+ 2 L-glutamate + NADP+
| 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 | ||||||||
| |||||||||
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.
References
- Temple SJ, Vance CP, Gantt JS (1998). "Glutamate synthase and nitrogen assimilation". Trends in Plant Science. 3 (2): 51–56. doi:10.1016/S1360-1385(97)01159-X.
- 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. 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.