Figure 1. GTP and GDP allosterically inhibit AgIMPDH.

(a) Analysis of the enzyme kinetics in vitro data using the linear Hanes-Woolf plot. Initial velocities (V_o) were determined by fitting the time-course data to the Michaelis–Menten equation. Reactions contained 20 μg ml⁻¹ AgIMPDH, 0.5 mM NAD⁺ and variable concentrations of IMP. Reaction buffer (100 mM Tris-HCl, 100 mM KCl, 2 mM DTT pH 8.0) did not contain Mg⁺². (b) Milligrams of inosine excreted per gram of mycelium from different strains of A. gossypii (1: WT, 2: ΔBateman and 3: P_GPD-ΔBateman) after 3 days of culture in MA2-rich medium at 28 °C with orbital shaking. Experiments were performed in triplicate. Error bars represent s.e.