Quorum-sensing bacteria communicate via small molecules called autoinducers to coordinate collective behaviors. Because quorum sensing controls virulence factor expression in many clinically relevant pathogens, membrane-permeable quorum sensing antagonists that prevent population-wide expression of virulence genes offer a potential route to novel antibacterial therapeutics. Here, we report a strategy for inhibiting quorum-sensing receptors of the widespread LuxR family. Structure-function studies with natural and synthetic ligands demonstrate that the dimeric LuxR-type transcription factor CviR from Chromobacterium violaceum is potently antagonized by molecules that bind in place of the native acylated homoserine lactone autoinducer, provided that they stabilize a closed conformation. In such conformations, each of the two DNA-binding domains interacts with the ligand-binding domain of the opposing monomer. Consequently, the DNA-binding helices are held apart by ∼60 Å, twice the ∼30 Å separation required for operator binding. This approach may represent a general strategy for the inhibition of multidomain proteins.
Hughson Lab Department of Molecular Biology Princeton University 201 Schultz Laboratory Washington Road Princeton, NJ 08544
Faculty Assistant Anna Schmedel 217 Schultz Laboratory p 609-258-5028 f 609-258-6730