Fig. 5.

RelA affects Hfq binding to RyhB in polysomal fractions. (A) Detection of RelA and Hfq in polysomal fractions extracted from the indicated strains using α-Hfq or α-RelA (using Western blotting). (B) RyhB binding by Hfq takes place in ribosomes of relA⁺ only. UV cross-linking of labeled RyhB incubated with ribosomes extracted from the indicated strains at 22 °C for 15 min is shown. The proteins were analyzed by SDS/PAGE as in Fig. 3A. Arrows indicate Hfq, S1, and PNPase proteins. Hfq protein bound to residues of labeled RyhB (Hfq*).