Involved in response to both electrophiles and reactive chlorine species (RCS) (PubMed:23506073, PubMed:23536188). Represses the transcription of the nemRA-gloA operon by binding to the NemR box (PubMed:18567656, PubMed:23506073, PubMed:23536188). May sense electrophiles, primarily quinones and glyoxals, as redox signals and regulate the redox state by modulating the expression of nemA and gloA (PubMed:23506073). Also uses the oxidation status of HOCl-sensitive cysteine residues to respond to bleach and related RCS (PubMed:23536188). Involved in response to methylglyoxal (PubMed:23646895). The redox state of the cysteines plays a crucial role in the regulation of NemR activity (PubMed:23506073, PubMed:23536188). Inactivated by reversible oxidation of cysteine residues in the presence of inducers such as quinones, glyoxals and reactive chlorine species (PubMed:23506073, PubMed:23536188). Also irreversibly inactivated by alkylation in the presence of N-ethylmaleimide (NEM) and other Cys modification reagents (PubMed:18567656). Inactivation by inducers decreases DNA-binding affinity and leads to the derepression of the nemRA-gloA operon (PubMed:18567656, PubMed:23506073, PubMed:23536188). Autoregulated (PubMed:18567656). Up-regulated by hypochlorous acid (HOCl), the active component of household bleach (PubMed:23536188). Cys-21 and Cys-116 form reversible intermolecular disulfide bonds in the presence of reactive electrophilic species (RES). Formation of disulfide bonds leads to dimerization of NemR, which alters DNA binding affinity and NemR activity. Oxidized on Cys-106. Reversible oxidative modification of Cys-106 plays the central role in the sensing of and response to bleach and other RCS (PubMed:23536188). It leads to the formation of a reversible sulfenamide bond between Cys-106 and Lys-175 (PubMed:25867078). Oxidation alters DNA binding affinity and NemR activity (PubMed:23536188). Deletion mutant is more resistant to methylglyoxal than wild-type strain.