Lon protease downregulates phenazine‐1‐carboxamide biosynthesis by degrading the quorum sensing signal synthase PhzI and exhibits negative feedback regulation of Lon itself in Pseudomonas chlororaphis HT66

What is it about?

Pseudomonas chlororaphis HT66 exhibits strong antifungal activity due to its main antibiotic phenazine-1-carboxamide (PCN). In the PCN gene cluster (phzI/phzR-phzABCDEFG-phzH), phzA-G operon is transcriptionally activated by the PhzI/R QS system. Here, we reported that Lon protease downregulates phzA-G expression and PCN biosynthesis by the AHL synthase PhzI. Lon directly degrades PhzI protein by recognizing the PhzI’s N-terminal 50 amino acids. Lon forms a negative feedback loop to modulate its own degradation by other potential proteases.

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