This Article Full Text Full Text (PDF) Supplemental material Other Versions of this Article: JB.00121-07v1 189/14/5002    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schaaf, S. Articles by Bott, M. Search for Related Content PubMed PubMed Citation Articles by Schaaf, S. Articles by Bott, M.

Target Genes and DNA-Binding Sites of the Response Regulator PhoR from Corynebacterium glutamicum ^,

Institut für Biotechnologie 1, Forschungszentrum Jülich, D-52425 Jülich, Germany

Received 23 January 2007/ Accepted 29 April 2007

The two-component signal transduction system PhoRS of Corynebacterium glutamicum is involved in the phosphate (P_i) starvation response. To analyze the binding of unphosphorylated and phosphorylated PhoR to the promoters of phosphate starvation-inducible (psi) genes, this response regulator and the kinase domain of its cognate sensor, PhoS (MBP-PhoS1-246), were overproduced and purified. MBP-PhoS1-246 showed constitutive autophosphorylation activity, and a rapid phosphoryl group transfer from phosphorylated MBP-PhoS1-246 to PhoR was observed. Gel mobility shift assays revealed that phosphorylation increases the DNA-binding affinity of PhoR. The affinity of PhoRP to different promoters varied and decreased in the order pstSCAB > phoRS > phoC > ushA > porB > ugpA > pitA > nucH and phoH1 > glpQ1. The binding sites in front of pstSCAB and phoRS were localized at positions –194 to –176 and –61 to –43 upstream of the transcriptional start sites, respectively. Alignment of these two 19-bp binding sites revealed a high identity in the 5'-terminal part, but not in the 3'-terminal part. As many OmpR-type response regulators bind to direct repeats, the 19-bp sequence might be interpreted as a loosely conserved 8-bp direct repeat separated by 3 bp. This idea was supported by the fact that the highest binding affinity was observed with a perfect 8-bp direct repeat of the sequence CCTGTGAAaatCCTGTGAA. Inspection of the other target promoters revealed sequences with some similarity to this binding motif, which might represent PhoR binding sites. The in vivo relevance of the PhoR-binding site within the phoRS promoter was supported by reporter gene studies.

Published ahead of print on 11 May 2007.

Supplemental material for this article may be found at http://jb.asm.org.

This article has been cited by other articles:

• Sola-Landa, A., Rodriguez-Garcia, A., Apel, A. K., Martin, J. F. (2008). Target genes and structure of the direct repeats in the DNA-binding sequences of the response regulator PhoP in Streptomyces coelicolor. Nucleic Acids Res 36: 1358-1368 [Abstract] [Full Text]