It has been experimentally verified that methylglyoxal (MG) and not NEM is the real inducer for the nemRA operon [4]. This induction was determined by ChIP-chip analysis with DNA-RNAP occupancy when cells were exposed to growth-inhibitory concentrations of MG [4]. NemR is a transcriptional repressor that is sensitive to HOCl and related reactive chlorine species (RCS), and its gene products contribute to increased bleach resistance by detoxifying reactive electrophiles produced during this process [5]. The NemR regulator is controlled by alkylation of one or more of its Cys residues. NemR contains five Cys residues, at positions 70, 78, 88, 121, and 125, in a total of 199 residues. In some of these residues, NemR is controlled by alkylation [1]. On the other hand, Lee et al. (2013) reported that NemR contains six cysteines located at residue positions 21, 98, 106, 116, 149, and 153 [6]. The critical Cys residue(s) involved in NemR activity control remains to be identified [1]. However, the cysteines at positions 21 and 116 have been determined as essential in sensing electrophiles in vivo and in vitro [6]. The Cys-106 residue, which is conserved among NemR homologs, has been identified as a trigger for the NemR RCS-sensing mechanism [5]. NemR is a redox-regulated transcriptional repressor, since it uses the oxidation status of HOCl-sensitive cysteine residues to respond to bleach and related reactive chlorine species (RCS) [5]. The NemR function is regulated by a Cys106-Lys175 sulfenamide thiol switch, upon RCS treatment of NemR [7]. Based on wide-scale analyses, the conservation of the TetR-family transcriptional regulators (TFTRs) across two genera, Escherichia and Salmonella, were analyzed and compared on three levels: genus, species, and strain. acrR, envR, and nemR TFTR genes were present in all Gram-negative species (Escherichia, Salmonella, P. aeruginosa, and K. pneumoniae), and these were denoted as core. On the other hand, slmA and ybiH genes were not present in all species but were present in all Escherichia and Salmonella species [8]. The majority of identified TFTRs are involved in efflux regulation, bleach survival, or biofilm formation [8]. Review: [9]