The emergence and global spread of antimicrobial resistance (AMR) is a significant threat to human, plant, and animal health. Central to the AMR problem are Gram-negative bacteria, which exhibit intrinsic resistance to many antibiotics due to their impermeable outer membrane (OM). A promising new avenue for antibiotic development targets the β-barrel assembly machinery (BAM), a conserved and essential protein complex present in all Gram-negative bacteria. BAM facilitates the insertion of β-barrel outer membrane proteins (β-OMPs) into the OM. These β-OMPs are crucial for functions like nutrient uptake, signalling, adhesion, and acting as virulence factors in pathogenesis. The surface-exposed nature of BamA makes it an attractive target for developing novel antibiotics, specifically lectin-like bacteriocins (Llps). Llps are bactericidal proteins naturally secreted by Gram-negative bacteria to eliminate competitors, and they are hypothesised to disrupt OM protein assembly by specifically binding to and disrupting the BAM complex. Utilising Pseudomonas spp., a ubiquitous and opportunistic pathogen, as a model organism, we aim to uncover the molecular mechanism of Llp killing. This will be achieved through a combination of phenotypic and proteomic analyses to determine the molecular effects of Llp treatment on cellular homeostasis. This project will provide comprehensive insights into the cytotoxicity of Llps produced by Pseudomonas spp.. In addition it will generate knowledge that will allow us to exploit the natural defences of Gram-negative bacteria to develop new therapeutic strategies to combat multidrug resistant pathogens.