(A) Portions of the rpsF operon assessed in this study. (B) β-galactosidase activity of (i) cells with no lacZ reporter transcript induced (−IPTG); (ii) (left axis) cells with the rpsF′-′lacZ transcript induced (+IPTG) and different portions of an exogenous rpsF-priB-rpsR transcript (including an empty vector control) induced (+arabinose) and uninduced (−arabinose); and (iii) (right axis) cells with the rpsO′-′lacZ transcript induced (+IPTG) with the empty vector and the rpsF-priB-rpsR transcript, induced and uninduced (±arabinose). Error bars represent the standard error of the mean for biological replicates. (C) Fold repression of the rpsF′-′lacZ reporter construct derived from data in B. Fold repression is calculated from matched pairs of cultures as (β-galactosidase activity −arabinose)/(β-galactosidase activity +arabinose). Error bars represent standard error of the mean for this calculation for biological replicates. (D) qRT-PCR quantification of the native transcript, rpsF-priB-rpsR-rplI (rplI), overexpressed transcript (rpsF), and reporter transcript (lacZ) relative to the tus control transcript. Error bars represent standard error of the mean for biological replicates.
