Fis represses transcription of the gyrA genes in E. coli .
) Discussion The finding that the sequences of S.enterica gyrA genes diverge significantly upstream of the -- 10 box of the promoter raised the possibility that the well-characterized Fis-mediated repression of gyrA transcription seen in E. coli might not be reproduced in S. enterica .
) Discussion The finding that the sequences of the E. coli gyrA genes diverge significantly upstream of the -- 10 box of the promoter raised the possibility that the well-characterized Fis-mediated repression of gyrA transcription seen in E. coli might not be reproduced in S. enterica .
Thus , Fis has the potential to act as a repressor at the S. enterica gyrA promoter by interfering with RNA polymerase binding , as it does in E. coli .
The retention of Fis-mediated repression of gyrA in S. enterica despite the radically different nucleotide sequence found immediately upstream of the Pribnow box is indicative of the physiological importance for the cell of regulation of gyrase expression by Fis .
the Fis protein is a repressor of gyrA transcription
In E. coli , FIS binds the gyrA promoters to repress their expression ; similarly , FIS has been found to repress S. enterica gyrA .