Download MendeleyStructure and DNA-Binding Properties of the Cytolysin Regulator CylR2 from Enterococcus Faecalis
Rumpel, S., Razeto, A., Pillar, C.M., Vijayan, V., Taylor, A., Giller, K., Gilmore, M.S., Becker, S., Zweckstetter, M.(2004) EMBO J 23: 3632
- PubMed: 15359276
- DOI: https://doi.org/10.1038/sj.emboj.7600367
- Primary Citation of Related Structures:
1UTX - PubMed Abstract:
Enterococcus faecalis is one of the major causes for hospital-acquired antibiotic-resistant infections. It produces an exotoxin, called cytolysin, which is lethal for a wide range of Gram-positive bacteria and is toxic to higher organisms. Recently, the regulation of the cytolysin operon was connected to autoinduction by a quorum-sensing mechanism involving the CylR1/CylR2 two-component regulatory system. We report here the crystal structure of CylR2 and its properties in solution as determined by heteronuclear NMR spectroscopy. The structure reveals a rigid dimer containing a helix-turn-helix DNA-binding motif as part of a five-helix bundle that is extended by an antiparallel beta-sheet. We show that CylR2 is a DNA-binding protein that binds specifically to a 22 bp fragment of the cytolysin promoter region. NMR chemical shift perturbation experiments identify surfaces involved in DNA binding and are in agreement with a model for the CylR2/DNA complex that attributes binding specificity to a complex network of CylR2/DNA interactions. Our results propose a mechanism where repression is achieved by CylR2 obstruction of the promoter preventing biosynthesis of the cytolysin operon transcript.
Organizational Affiliation:
Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
