title: The MerR family of transcriptional regulators.
abstract: The MerR family is a group of transcriptional activators with similar N-terminal helix-turn-helix DNA binding regions and C-terminal effector binding regions that are specific to the effector recognised. The signature of the family is amino acid similarity in the first 100 amino acids, including a helix-turn-helix motif followed by a coiled-coil region. With increasing recognition of members of this class over the last decade, particularly with the advent of rapid bacterial genome sequencing, MerR-like regulators have been found in a wide range of bacterial genera, but not yet in archaea or eukaryotes. The few MerR-like regulators that have been studied experimentally have been shown to activate suboptimal sigma(70)-dependent promoters, in which the spacing between the -35 and -10 elements recognised by the sigma factor is greater than the optimal 17+/-1 bp. Activation of transcription is through protein-dependent DNA distortion. The majority of regulators in the family respond to environmental stimuli, such as oxidative stress, heavy metals or antibiotics. A subgroup of the family activates transcription in response to metal ions. This subgroup shows sequence similarity in the C-terminal effector binding region as well as in the N-terminal region, but it is not yet clear how metal discrimination occurs. This subgroup of MerR family regulators includes MerR itself and may have evolved to generate a variety of specific metal-responsive regulators by fine-tuning the sites of metal recognition.
authors.affiliation: School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK. n.l.brown@bham.ac.uk
authors.forename: Nigel L
authors.initials: NL
authors.lastname: Brown
authors.forename: Jivko V
authors.initials: JV
authors.lastname: Stoyanov
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Kidd
authors.forename: Jon L
authors.initials: JL
authors.lastname: Hobman
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019143:Evolution, Molecular; D005798:Genes, Bacterial / Q000235:genetics; D008670:Metals / Q000378:metabolism; D008957:Models, Genetic; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D014157:Transcription Factors / Q000737:chemistry / Q000145:classification / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C051124:MerR protein, Bacteria; D008670:Metals; D014157:Transcription Factors