Enterococcus faecalis virulence regulator FsrA binding to target promoters

DEL PAPA M. F.; PEREGO M.

JOURNAL OF BACTERIOLOGY

AMER SOC MICROBIOLOGY

Año: 2011 vol. 97 p. 1527 - 1532

0021-9193

The FsrABDC signal transduction system is a major virulence regulator in Enterococcus  faecalis. The FsrC sensor histidine kinase, upon activation by the GBAP peptide encoded by the fsrBD genes, phosphorylates the FsrA response regulator required for the transcription of the fsrBDC and the gelE-sprE genes from the fsrB promoter and the gelE promoter, respectively. FsrA belongs to the LytTR family of proteins which includes other virulence regulators such as AgrA of Staphylococcus aureus, AlgR of Pseudomonas aeruginosa, and VirR of Clostridium perfringes. The LytTR DNA-binding domain that characterizes these proteins generally binds to two imperfect direct repeats separated by a number of bases that place the repeats on the same face of the DNA helix. In this study we demonstrated that FsrA also binds to two imperfect direct repeats based on the consensus sequence T/AT/CAA/GGGAA/G, and separated by 13 base pairs, consistent with the binding characteristics of LytTR domains.