Fig. 4
From: Uncoupling conformational states from activity in an allosteric enzyme
Competition between TIH and l-His. a ATP-PRT activity in the absence of l-His (green bar), in the presence of an l-His concentration equivalent to 20-fold K i (0.4 mM; star) and in the presence of 0.4 mM l-His plus increasing concentrations of TIH (dark red and cyan bars, K A = 2 mM). Error bars indicate the s.d., n = 3. b Contour plot of ATP-PRT activity landscape in the presence of both l-His and TIH. c STD-NMR of TIH and l-His with 20 μM ATP-PRT. TIH concentration was kept at 400 μM, while the concentration of l-His was varied, 0, 50, 100, 150, 400, 800, 1600 and 3000 μM, from the blue bottom trace, to the black top trace. Experiments were performed in 50 mM sodium phosphate buffer at pH 8.0. Red and navy blue triangles indicate ATP-PRT occupancy by l-His and TIH, respectively
