Glutamate synthase (NADPH)

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


 * L-glutamine + 2-oxoglutarate + NADPH + H+ $$\rightleftharpoons$$ 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.

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.