<p> Members of this family are IclR-type transcriptional regulators with similar DNA binding sites, able to bind at least three different metabolites related to protocatechuate metabolism. Beta-ketoadipate is the inducer for PcaR, p-hydroxybenzoate for PobR, and protocatechuate for PcaU.</p> Beta-ketoadipate transcriptional regulator, PcaR/PcaU/PobR