Overexpression of SraG represses pnp expression. Isogenic FF4 (wt) and FF19 (rnc) strains carrying the pnp-lacZ fusion were transformed with the pBRplac (pBR), pBR-SraG (pBRSraG), and pBR-SraG short (pBRSraG-S) plasmids. SraG and SraG-S synthesis were induced by addition of IPTG at the beginning of the cultures. Samples were taken in the middle of the exponential phase to determine β-galactosidase activity and PNPase levels. (A) β-Galactosidase activity is the mean value of three independent cultures with standard deviation. (B) Western blot analysis of PNPase and L20 has been made on FF4 strain (wt). Quantification of PNPase normalized to L20 is indicated below the gel.
