Fig. 2: Darobactin A binds the SAM complex with higher affinity than linear darobactin.
Chemical structures of A darobactin A and B linear darobactin. Representative MST fluorescence curves for one technical replicate of SAM complex titration with C darobactin A or D linear darobactin. Highest (dark pink) and lowest (light pink) tested ligand concentrations are indicated. Data are representative of three (linear darobactin) or six (darobactin A) independent replicates. E Merged dose response data from SAM complex binding darobactin A (circle data points, solid line fit) or linear darobactin (square data points, dashed line fit). Highest (dark pink) and lowest (light pink) tested ligand concentrations are indicated. Each plotted datapoint is an average of 2–3 technical replicates. Data are representative of three independent replicates. F Comparison of Kd values determined for TtSAM complex interactions with darobactin A (n = 6), linear darobactin (n = 3), TtTom40 β-signal peptide (n = 3), and TtPorin1 β-signal peptide (n = 3). Each point represents the mean Kd of one biological replicate, calculated from 2 to 3 technical replicates. Error bars are calculated based on standard error of regression for each biological replicate. Highest concentrations of linear darobactin were not saturating, notated by arrow above linear darobactin data points. Data in (C–E) are representative for three (linear darobactin, Por1 β-signal peptide, and Tom40 β-signal peptide) or six (darobactin A) independent experiments. Kd and fit values from all biological replicates can be found in Supplementary Table 1. Peptide information including sequences can be found in Supplementary Table 2. Replicate data and source data are provided as a Source Data file.
