Helix-Turn-Helix DNA binding domain of BmrR-like transcription regulators
Helix-turn-helix (HTH) BmrR-like transcription regulators (TipAL, Mta, SkgA, BmrR, and BltR), N-terminal domain. These proteins have been shown to regulate expression of specific regulons in response to various toxic substances, antibiotics, or oxygen radicals in Bacillus subtilis, Streptomyces, and Caulobacter crescentus. They are comprised of two distinct domains that harbor the regulatory (effector-binding) site and the active (DNA-binding) site. Their conserved N-terminal domains contain HTH motifs that mediate DNA binding, while the C-terminal domains are often unrelated and bind specific coactivator molecules. These proteins share the N-terminal DNA binding domain with other transcription regulators of the MerR superfamily that promote transcription by reconfiguring the spacer between the -35 and -10 promoter elements.