Crystal Structure of Bacillus cereus HlyIIR, a Transcriptional Regulator of the Gene for Pore-forming Toxin Hemolysin II.
Kovalevskiy, O.V., Lebedev, A.A., Surin, A.K., Solonin, A.S., Antson, A.A.(2007) J Mol Biol 365: 825-834
- PubMed: 17097673 
- DOI: https://doi.org/10.1016/j.jmb.2006.10.074
- Primary Citation of Related Structures:  
2FX0 - PubMed Abstract: 
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 A(3) 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.
Organizational Affiliation: 
Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia.