Figure 6.

Identification of a chemical inhibitor of Alg44_PilZ binding to c-di-GMP.

(A) Representative image of DRaCALA spots from one screening plate. Spot boxed in red corresponds to a well that contained a compound that inhibited His-MBP-Alg44_PilZ binding to ³²P-c-di-GMP. Spots boxed in green and blue correspond to wells containing 5 μM unlabeled c-di-GMP and DMSO, respectively. Inset shows a zoomed image of the indicated area. (B) FB is plotted in order of position for the entire 384-well plate. Red star corresponds to the red-boxed well in (A). Blue circles correspond to wells containing DMSO solvent only. Green open and closed circles correspond to wells containing 5 μM and 10 μM unlabeled c-di-GMP, respectively. Green line represents the average F_B of the wells containing test compounds. Dashed line represents the 3 standard deviation cutoff for classification of hit compounds. The compound identified from screening this plate was AC1LFHI9 (HI9), a derivative of thiol-benzo-triazolo-quinazolinone. Adapted with permission from Zhou et al. (2017).