Fig 3.

Overexpression of ramA represses the ramA promoter activity. The exponentially growing cells were supplemented with IPTG (0 h). The strains used carried the PramA-lacZ fusion in the chromosome in the genetic background of the wild type (filled circles), ramA mutant transformed with pCRC622 for IPTG-inducible ramA expression (open squares), and ramA-sugR mutant transformed with pCRC622 (open triangles). Changes in the levels of ramA (top), lacZ (middle), and sugR (bottom) mRNAs were analyzed using qRT-PCR. The mRNA levels in the ramA mutant carrying pCRC622 cultured in the absence of IPTG throughout are also shown (filled squares). The mRNA levels are presented relative to the value obtained from the wild type carrying PramA-lacZ before IPTG supplementation (0 h). Mean values obtained from at least three independent cultivations are shown with standard deviations.