Importantly , the enrichment in ssrB promoter DNA was comparable to that of other known PmrA-regulated genes , including pmrC ( Fig. 4C ) .
This analysis suggested that PmrA might bind to the ssrB promoter .
Second , chromatin immunoprecipitation experiments revealed that an HA-tagged PmrA bound to the ssrB promoter in-vivo .
The PmrA protein directly binds to a specific sequence in the promoter of ssrB , repressing its expression .
To identify the binding of PmrA to the promoter region of the ssrB gene were carried out as described .
Interestingly , the PmrA protein repressed SPI-2 expression in a manner similar to the Fur regulator ; PmrA was shown to bind to a region overlapping with the SsrB-binding site on the ssrB promoter .