We also determined that the Fur protein was acting as a transcriptional repressor of the feoAB operon because deletion of the fur gene resulted in a twofold increase of Fig. 2A .
We also determined that the Fur protein was acting as a transcriptional repressor of the feoAB operon because deletion of the fur gene resulted in a twofold increase of the wild-type feoAB transcripts .
Fur directly binds to the hilD promoter and enhances its own expression ( 15 ) , and HilD functions as an activator of SPI-1 expression ( 17 ) .