MerR
MerR is a family of metal-responsive transcriptional regulators found in bacteria. The prototype is MerR, which regulates the mercury resistance operon by sensing Hg2+ and activating detoxification genes such as merA, which encodes mercuric reductase, and merT and merP, which encode transport proteins.
MerR family proteins function as homodimers that bind specifically to operator sequences overlapping the promoter region
Structurally, MerR proteins have an N-terminal DNA-binding helix-turn-helix domain, a central dimerization/coil region, and a C-terminal
Beyond mercury resistance, the MerR family includes regulators that respond to other metals and metalloids, such
MerR regulons contribute to bacterial detoxification of toxic metals and to metal homeostasis, and are commonly
MerR-based biosensors exploit the metal-responsive DNA-distortion mechanism to detect mercury contamination with high sensitivity and tunability.