FIGURE 6.
SraG blocks 30S binding to the pnp 5′-leader in vitro. In vitro synthesized pnp RNA fragment (positions 1–234 relative to the transcription start) was used in a toe-print assay in the presence and absence of SraG and SraG-S RNAs. pnp RNA was incubated with increasing concentrations of SraG or SraG-S (as a control RNA) giving a molar ratio sRNA:pnp RNA of 0 (lanes 1, 6, 11, 16), 0.5 (lanes 2, 7, 12, 17), 1 (lanes 3, 8, 13, 18), 2 (lanes 4, 9, 14, 19), and 5 (lanes 5, 10, 15, 20). Addition of tRNAfMet and 30S ribosomal subunits is indicated by (+) (lanes 11–20). GATC lanes are sequencing ladders obtained by asymmetric PCR using the same labeled primer. The TTG start codon of pnp is shown. The arrow indicates the 30S toe-print on the pnp RNA.