Positive regulatory factor A (PrfA) (PrfA)

Positive regulatory factor A (PrfA) is the master transcriptional regulator of virulence in the Gram-positive pathogen Listeria monocytogenes [1, 4]. It coordinates the expression of the PrfA regulon, a suite of genes essential for the bacteria's ability to invade host cells, escape the phagosome, and replicate intracellularly [4, 7]. The protein's activity is tightly controlled by environmental cues, particularly temperature (37°C) and the allosteric binding of reduced glutathione (GSH), which triggers a conformational shift to a high-affinity DNA-binding state [12, 14]. Because PrfA is indispensable for pathogenicity but not for survival outside the host, it is considered a prime target for anti-virulence therapeutics [5, 12]. Experimental inhibitors, such as ring-fused 2-pyridones (e.g., C16 and PS900), have demonstrated the ability to 'disarm' the pathogen by preventing the activation of its virulence program [13, 15, 18]. This therapeutic approach offers a potential alternative to traditional antibiotics, potentially reducing the selective pressure for resistance while preserving the host's commensal microbiome [13].

Other names

Positive regulatory factor AListeriolysin positive regulatory factor AVirulence regulator PrfAPrfA proteinTranscriptional activator PrfA

Small molecule inhibitors function as allosteric or competitive antagonists that block the binding of reduced glutathione (GSH) to the PrfA protein, preventing it from transitioning into its active DNA-binding conformation and thereby suppressing the transcription of virulence factors.