To circumvent this issue and facilitate the examination of YdcRregulated srfN transcription in-vitro , we further introduced a YdcR-expressing plasmid into the ydcR strain , whose expression is under the control of arabinose .
Furthermore , we found evidence that YdcR directly control its expression on the transcriptional level by binding to the promoter region of the srfN gene .
Futhermore,-galactosidase assays were used to establish the transcriptional control of the srfN gene by YdcR .
Taken together , these results indicate that YdcR controls the expression of the srfN gene at the transcriptional level .
First , we used qRT-PCR to measure the transcript levels of srfN and found the regulation of YdcR on the expression of SrfN indeed occurs on the transcriptional level .
Further-galactosidase assays of Sal-monella strains also confirmed that YdcR can mediate transcriptional regulation of srfN in bacteria .