Prokaryotic glutathione synthetase <db_xref db="EC" dbkey="6.3.2.3"/> (glutathione synthase) catalyses the conversion of gamma-L-glutamyl-L-cysteine and glycine to orthophosphate and glutathione in the presence of ATP. This is the second step in glutathione biosynthesis. The enzyme is inhibited by 7,8-dihydrofolate, methotrexate and trimethoprim. This is the ATP-binding domain of the enzyme.