This family of bacterial transcriptional repressors is characterised by the short approximately 50 amino acid stretch of residues constituting the helix-turn-helix DNA binding motif, around the YRFhY motif. The target proteins that are repressed are involved in the transcriptional control of multi-drug efflux pumps, pathways for the biosynthesis of antibiotics, response to osmotic stress and toxic chemicals, control of catabolic pathways, differentiation processes, and pathogenicity [1].

1: The TetR family of transcriptional repressors. Ramos JL, Martinez-Bueno M, Molina-Henares AJ, Teran W, Watanabe K, Zhang X, Gallegos MT, Brennan R, Tobes R; Microbiol Mol Biol Rev. 2005;69:326-356. PMID:15944459