... affect the binding of ATP to GlnK [12]. Therefore, we investigated the binding of TnrA to GlnK in the presence of differentmixtures of Mg2+or Mn2+with the effector moleculesATP and 2-oxoglutarate. ... in uence the GlnK–TnrA interaction, either alone, in the absence of divalent metals, or in combination withATP and Mg2+or Mn2+. To resolve the inhibitoryeffect of ATP on the GlnK–TnrA interaction ... [1,9]. The feedback-inhibited form of GSbinds tightly to TnrA, preventing its binding to DNA,with the most effective feedback inhibitors of GS beingglutamine and AMP [9]. Mutations in TnrA...