Accessory gene regulator A (AgrA)

Accessory gene regulator A (AgrA) is a critical response regulator in the Staphylococcus aureus agr quorum-sensing system, acting as a DNA-binding transcription factor that controls the switch between colonization and virulence (UniProt P0C1P1). It is activated through phosphorylation by the sensor kinase AgrC in response to high concentrations of autoinducing peptides (AIPs). Once activated, AgrA binds to the P2 and P3 promoters, driving the expression of the agr operon and RNAIII, which in turn regulates the production of a wide array of toxins, including alpha-hemolysin and phenol-soluble modulins (Sully et al., 2014). As a therapeutic target, AgrA is central to anti-virulence strategies aimed at neutralizing bacterial pathogenicity without directly killing the bacteria, thereby potentially reducing the selective pressure for antibiotic resistance (Khodaverdian et al., 2013). Experimental inhibitors like Savirin have demonstrated the ability to bind AgrA and prevent its interaction with DNA, effectively attenuating infection in animal models (Sully et al., 2014).

Other names

Response regulator AgrAagrATranscriptional activator AgrAStaphylococcus aureus AgrA

Inhibition of DNA binding to P2 and P3 promoters, preventing the transcription of the agr operon and RNAIII effector molecules.