Fig. 4.

Functional effects exerted by the truncated RyhB. (A) Predicted minimal free-energy structure of the mutant RyhBt, which is truncated of the first hairpin and the linker region of the wild-type RyhB (Fig. S1). (B) Relative expression of the chromosomally encoded RyhB and RyhBt in hfq⁺ (blue and red bars) and hfq⁻ background (green and black bars). (C and D) Effect of chromosomally expressed RyhB and RyhBt on the expression of various endogenous targets (sodB, fumA, sdhD, and sucA) in hfq⁺ strains (C) and hfq⁻ strains (D). sRNA and mRNA abundances were determined using quantitative real-time PCR in strains harboring chromosomal P_LTet-o1:ryhB (strain ZZS0R, ZZS0Rq, blue and green bars) or P_LTet-o1:ryhBt (strain ZZS0T, ZZS0Tq, red and black bars). Open and solid bars refer to results from cells grown with 10 ng/mL and no aTc, respectively. For each RNA species characterized, the abundance was normalized to the level of 16S RNA (encoded by rrsB), which is relatively constant in the different strains and conditions. In C and D the mRNA abundances were given relative to the mRNA level in strain ZZS0T grown with no aTc. The numerical values are listed in Tables S13, S14, and S15.