1UTX

Regulation of Cytolysin Expression by Enterococcus faecalis: Role of CylR2

Summary for 1UTX

• Entry DOI: 10.2210/pdb1utx/pdb
• Descriptor: CYLR2, IODIDE ION, SODIUM ION, ... (4 entities in total)
• Functional Keywords: dna-binding protein, transcriptional repressor, regulation of cytolysin operon, helix-turn-helix, dna binding protein
• Biological source: ENTEROCOCCUS FAECALIS
• Total number of polymer chains: 2
• Total formula weight: 16615.10

Authors

Razeto, A.,Rumpel, S.,Pillar, C.M.,Gilmore, M.S.,Becker, S.,Zweckstetter, M. (deposition date: 2003-12-12, release date: 2004-09-16, Last modification date: 2024-05-08)

Primary citation

Rumpel, S.,Razeto, A.,Pillar, C.M.,Vijayan, V.,Taylor, A.,Giller, K.,Gilmore, M.S.,Becker, S.,Zweckstetter, M.
Structure and DNA-Binding Properties of the Cytolysin Regulator CylR2 from Enterococcus Faecalis
Embo J., 23:3632-, 2004

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.

PubMed: 15359276
DOI: 10.1038/SJ.EMBOJ.7600367

Experimental method

X-RAY DIFFRACTION (1.9 Å)