FIG. 4.
CsrA and 30S ribosomal subunit toeprint analysis of hfq RNA. The concentration of CsrA used in each reaction mixture, as well as the absence (−) or presence (+) of tRNAfMet and 30S ribosomal subunits (30S Rib), is shown at the top of each lane. CsrA was added prior to 30S ribosomal subunits when both were present in the same reaction mixture. Arrows identify CsrA-dependent and 30S ribosomal subunit (Rib) toeprint bands. An additional 30S ribosomal subunit-dependent toeprint is marked (*). Positions of the hfq SD sequence and the translation initiation codon (AUG) are shown. The RNA segment corresponding to h1 is also shown. Sequencing lanes to reveal G, U, A, or C residues are marked. Numbering is from the start of hfq transcription.