This bacterial enzyme adenylates a tyrosine residue of EC
6.3.1.2, glutamine synthetase. The enzyme is bifunctional, and also catalyses a reaction that removes the adenyl group from the modified tyrosine residue (cf. EC
2.7.7.89, [glutamine synthetase]-adenylyl-L-tyrosine phosphorylase) [7,8]. The two activities are present on separate domains.