This domain is found in type III glutamine synthetase present in Bacteroides fragilis. Glutamine synthetase (GS) are large oligomeric enzymes that catalyze the condensation of ammonium and glutamate to form glutamine, the principal source of nitrogen for protein and nucleic acid synthesis. This domain is located in the C-terminal end of the protein [1].

1: Crystal structure of Type III glutamine synthetase: surprising reversal of the inter-ring interface. van Rooyen JM, Abratt VR, Belrhali H, Sewell T; Structure. 2011;19:471-483. PMID:21481771