The rcsA promoter of Pantoea stewartii subsp stewartii features a low-level constitutive promoter and an EsaR quorum-sensing-regulated promoter

The upstream region of the Pantoea stewartii rcsA gene features two promoters, one for constitutive basal-level expression and a second autoregulated promoter for induced expression. The EsaR quorum-sensing repressor binds to a site centered between the two promoters, blocking transcription elongation from the regulated promoter under noninducing conditions.