Figure 5.

Hit compound competition with adenosine triphosphate (ATP) and lysine for active site binding. In aminoacylation assays containing BM01D09, the IC₅₀ values increased as the concentration of ATP was increased, indicating competitive inhibition (A). In competition assays containing BT08F04, the IC₅₀ values increased with increasing concentrations of ATP, indicating competitive inhibition (B), and decreased when the concentration of lysine increased, which is characteristic of an uncompetitive inhibitor (C). P. aeruginosa lysyl-tRNA synthetase (LysRS) concentration was set at 0.01 μM in these assays. Background amounts of free [³H]Lys in the absence of LysRS were insignificant.