FIGURE 6.

Full-length NusA favors but does not require exit channel duplexes with upstream ssRNA for enhancement of PEC lifetime. Pause stimulation by the antisense 8-mer RNA oligo, RNA oligos with single strand tails (U-tail EC), and RNA oligos with double strand tails (Hairpin-tail EC). ECs were shown in Fig. 2B (see “Experimental Procedures”). Antisense 8-mer RNA oligo, U-tail antisense RNA oligo, and hairpin-tail antisense RNA oligo were added to 1 μm or 32 μm to generate the 8-bp EC, U-tail EC, and hairpin-tail EC, respectively. Pause half-lives were measured as in the preceding figures (see “Experimental Procedures”) in the absence of NusA, with full-length NusA (2.5 μm) or NusA-NTD (residues 1–137; 4 μm). Error bars, S.D.