Acyl-homoserine lactone (AHL) is the most studied autoinducer in gram-negative bacteria controlling infections of various pathogens. Quenching of AHL signaling by inhibiting AHL synthesis or AHL-receptor binding via small molecular chemicals or enzymatically degrading AHL is commonly used to block bacterial infections. Here, we describe a new quorum-quenching strategy that directly "acquires" bacterial genes/proteins through a defined platform. We artificially expressed a typical AHL synthase gene pcoI from the biocontrol Pseudomonas fluorescens 2P24 in the antifungal bacterium Lysobacter enzymogenes OH11 lacking AHL production. This step led to the discovery of multiple PcoI interacting protein candidates from L. enzymogenes. The individual expression of these candidate genes in 2P24 led to the identification of Le0959, which encodes leucyl aminopeptidase, an effective protein that inhibits AHL synthesis in 2P24. Therefore, we define Le0959 as LqqP (Lysobacterquorum-quenching protein). The expression of pcoI in E. coli could produce AHL, and the introduction of lqqP into E. coli expressing pcoI could prevent the production of AHL. LqqP directly binds to PcoI, and this protein-protein binding reduced the abundance of free PcoI (capable of AHL synthesis) in vivo, thereby blocking PcoI-dependent AHL production. Overall, this study highlights the discovery of LqqP in quenching AHL quorum sensing by binding to AHL synthase via developing a previously-uncharacterized screening technique for bacterial quorum quenching.
Pubmed ID: 34900131 RIS Download
Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.