FIG. 3.

The sRNA chaperone Hfq is necessary for LrhA repression of rpoS translation. In the hfq::kan background, the lrhA49::cam allele (CNP213) did not reduce RpoS levels compared to those found in the lrhA⁺ background (CNP215), as determined by Western blotting. However, the lrhA::spc allele (CNP214) still had a positive effect on RpoS levels. A sprE::tet background was used for these experiments to increase the overall levels of RpoS, since the hfq mutation has a negative effect on RpoS synthesis and lowers its levels to below the detection threshold in wild-type cells. All samples were collected from cells growing exponentially in LB rich medium.