Carries out the ATP-dependent synthesis of glutamine from ammonium nitrogen and glutamate. Exhibits both L-gamma-glutamylhydroxamate synthetase and gamma-glutamyltransferase activities when using hydroxylamine as substrate; in fact, the enzyme possesses low biosynthetic activity, suggesting that the reaction is biased towards the degradation of glutamine under ammonia-rich conditions. Might play some role in ammonia assimilation under ammonia-starvation conditions. Can also use GTP instead of ATP in the synthetase reaction, but not CTP or UTP. ATP + L-glutamate + NH4(+) = ADP + H(+) + L-glutamine + phosphate ATP + hydroxylamine + L-glutamate = ADP + L-glutamine hydroxamate + phosphate Binds 2 Mg(2+) or Mn(2+) ions per subunit. The activity of this enzyme is not controlled by adenylation. kcat is 2190 min(-1) towards L-glutamate in the synthetase reaction and 3900 min(-1) towards L-glutamine in the transferase reaction. Optimum pH is 7.8 for the synthetase reaction and pH 7.2 for the transferase reaction. Optimum temperature is 60 degrees Celsius for both transferase and synthetase activities. Oligomer of 12 subunits arranged in the form of two hexagons. Belongs to the glutamine synthetase family.