... more than 50% of the GlnK–TnrA interaction in the presence of 2 mm ATP.On the other hand, 2-oxoglutarate did not influence the GlnK–TnrA interaction, either alone, in the absence of divalent metals, ... the complex following the injection phase (Fig. 2A). In the course of the mea-surements, we found that 2 mm ATP (in the absence of Mg2+) led to rapid dissociation of the GlnK–TnrAcomplex ... resolve the inhibitoryeffect of ATP on the GlnK–TnrA interaction in the absence of divalent cations more clearly, ATP wastitrated to the binding assays in the absence or pres-ence of 2-oxolguatarate....