As expected , expression of known AraC-regulated genes , i.e. , araB , araA , araD , araE , araF , araG , araH , and araJ , increased substantially upon addition of arabinose in wild-type cells and was substantially higher in wildtype cells than araC cells in the presence of arabinose ( Table 2 ) .
Together with a bioinformatic analysis of other Enterobacteriaceae species , these data identify a conserved AraC regulon that includes 7 previously described AraC-regulated genes ( araB , araA , araD , araE , araF , araG , and araH ) as well as three novel targets identified in this work ( ytfQ , araT , and araU ) .
To determine whether either ydeM is required for normal regulation of AraC-activated genes , we constructed a translational fusion of the araE upstream region to measured-galactosidase activity in a wildtype strain and in isogenic strains containing deletions of either ydeM .
To determine whether either ydeM is required for normal regulation of AraC-activated genes , we constructed a translational fusion of the araE upstream region to lacZ activity in a wildtype strain and in isogenic strains containing deletions of either ydeM .
To determine whether either ydeN is required for normal regulation of AraC-activated genes , we constructed a translational fusion of the araE upstream region to measured-galactosidase activity in a wildtype strain and in isogenic strains containing deletions of either ydeN .
To determine whether either ydeN is required for normal regulation of AraC-activated genes , we constructed a translational fusion of the araE upstream region to lacZ activity in a wildtype strain and in isogenic strains containing deletions of either ydeN .
If suppression of SPI-1 regulation by L-arabinose in AraCˉ background was due to lack of AraE permease , an araE mutation should be epistatic over an araC mutation .