The graph depicts the displacement of the MANT-ADP by unmodified ADP as followed by a decrease in the FRET signal associated with the binding of the MANT-ADP (10 μM) to YjeE (6 μM). The data were fitted to a hyperbolic function to determine the Kapp. The inset summarizes the Kapp measured for ADP, AMPPNP and AMP. No displacement was detected when GMP, GDP, GTP, CMP, CDP, CTP, UMP, UDP or UTP was used as a competitor.