Production of Bacillus cereus and Bacillus anthracis toxins is controlled by a number of transcriptional regulators. Here we report the crystal structure of B. cereus HlyIIR, a regulator of the gene encoding the pore-forming toxin hemolysin II. We show that HlyIIR forms a tight dimer with a fold and overall architecture similar to the TetR family of repressors. A remarkable feature of the structure is a large internal cavity with a volume of 550 Å3 suggesting that the activity of HlyIIR is modulated by binding of a ligand, which triggers the toxin production. Virtual ligand library screening shows that this pocket can accommodate compounds with molecular masses of up to 400-500 Da. Based on structural data and previous biochemical evidence, we propose a model for HlyIIR interaction with the DNA. © 2006 Elsevier Ltd. All rights reserved.
Kovalevskiy, O. V., Lebedev, A. A., Surin, A. K., Solonin, A. S., & Antson, A. A. (2007). Crystal Structure of Bacillus cereus HlyIIR, a Transcriptional Regulator of the Gene for Pore-forming Toxin Hemolysin II. Journal of Molecular Biology, 365(3), 825–834. https://doi.org/10.1016/j.jmb.2006.10.074