X-ray crystal structure of glycinamide ribonucleotide synthetase from Escherichia coli

The x-ray crystal structure of glycinamide ribonucleotide synthetase (GAR-syn) from Escherichia coli was described. Results revealed that GAR-syn is a member of the ATP-grasp superfamily. Its structure was sterically and electrostatically compatible with the binding surface proposed to be important in amidotransferase (AT). The N domain of GAR-syn was opposite to the flexible loop region of AT that can adopt several conformations and appeared ready to gate phosphoribosylamine release.