Glutamate-cysteine ligase

In enzymology, a glutamate-cysteine ligase is an enzyme that catalyzes the chemical reaction


 * ATP + L-glutamate + L-cysteine $$\rightleftharpoons$$ ADP + phosphate + gamma-L-glutamyl-L-cysteine

The 3 substrates of this enzyme are ATP, L-glutamate, and L-cysteine, whereas its 3 products are ADP, phosphate, and gamma-L-glutamyl-L-cysteine.

This enzyme belongs to the family of ligases, specifically those forming carbon-nitrogen bonds as acid-D-amino-acid ligases (peptide synthases). The systematic name of this enzyme class is L-glutamate:L-cysteine gamma-ligase (ADP-forming). Other names in common use include gamma-glutamylcysteine synthetase, gamma-glutamyl-L-cysteine synthetase, and gamma-glutamylcysteinyl synthetase. This enzyme participates in glutamate metabolism and glutathione metabolism. At least one compound, S-Butyl-DL-homocysteine-[S,R]-sulfoximine is known to inhibit this enzyme.

Structural studies
As of late 2007, 6 structures have been solved for this class of enzymes, with PDB accession codes, , , , , and.