Figure 1.

QEN blocks the thioesterification process of SrtA catalysis, but does not inhibit bacterial physiology. (A) The chemical structure of QEN. (B) The growth curve of S. aureus treated with or without QEN. S. aureus were cultured in BHI without QEN or with 256 μg/mL QEN, and the absorbency readings of the samples were taken at OD₆₀₀ at the indicated time point. (C) QEN blocks the catalytic activity of SrtA. The fluorescent peptide was incubated with purified SrtA treated with the indicated concentrations of QEN at 37 °C for 30 min, and the fluorescence was measured 1 h after adding the substrate-modified peptide.