Antibacterialagent 284 (Compound 7) is an antibacterial agent with a zinc-binding structure, showing potent inhibitory activity against the Legionella pneumophila metalloprotease ProA, with an IC50 of 0.96 μM. It effectively inhibits the cleavage of type IV collagen and flagellin (ProA substrates), and reduces immune evasion within the TLR5-NF-κB pathway and neutrophil (PMN)-mediated inflammation in human lung tissue explants. Antibacterialagent 284 holds potential for Legionnaires' disease research.