Fig. 4: Functional analysis of FprB in Ga(NO3)3 resistance in P. aeruginosa.
From: CRISPRi screen identifies FprB as a synergistic target for gallium therapy in Pseudomonas aeruginosa
a Growth curve of PAO1 wild type, ΔfprB and complemented strain (ΔfprB-Com) in the absence and presence of 12.5 μM Ga(NO3)3. b Plate spot assays showing sensitivity of PAO1 wt, ΔfprB, and ΔfprB-Com strains to gallium. c Time-kill assay of P. aeruginosa treated with Ga(NO3)3 in LB broth. Bacterial counts were determined at indicated timepoints by serial dilutions and plating on LB agar plates. d Reaction kinetic traces for determining FprB activity by 2,6-dichlorophenolindophenol (DCPIP)-diaphorase assay. e Molecular docking of FprB with FAD. Structure of FprB was predicted by Alphafold3 following molecular dynamics refinement. FAD is shown in Corey-Pauling-Koltun (CPK) colored sticks with carbons in light blue. The FprB amino acids predicted near FAD are indicated. f, g Impact of putative FAD binding disrupting amino acid changes (A57G, Y58A, F72A, and I74A) in FprB on P. aeruginosa’s resistance to Ga(NO3)3 treatment. Growth characteristics were determined by serial dilutions followed by dropping onto LB agar plates (f) or by growth using a microplate reader (g). Data from all growth and measurement assays are presented as mean ± SD from three biological replicates. Source data are provided as a Source Data file.
