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⁺ ${\displaystyle \rightleftharpoons }$ 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
Search PMC articles PubMed articles NCBI proteins

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)