Fig. 5
Reconstituted PhrS-mediated anti-termination acts on CRISPR2 locus. a PhrS sRNA inhibits Rho termination at leader sequence of CRISPR2 locus in vitro. Preformed elongation was transcribed without (lane 1 and 5) or with (lane 2–4) Rho and NusG. The Rho-dependent termination was estimated without (lane 2) or with PhrS sRNA (lane 3) or BCM (lane 4). The bracket represents termination regions (T). b Diagram of CRISPR leader with lacZ ORF and CRISPR array. The fragments for qRT-PCR are labeled as green. The dynamic value of [UTR]/[ORF] was used to assess termination efficiency of Rho-dependent termination by PhrS in CRISPR leader, normalized by CRISPR array and lacZ RNA. Increased value represents more termination efficiency, but a lower value indicates reduction of termination efficiency. c Transcript expression of various lacZ zones quantified for PA14 WT or ΔphrS before and after BCM treatment. d Levels of CRISPR array measured for the PA14 Δcsy4 and Δcsy4/ΔphrS mutant. e Transcript expression of various CRISPR locus zones quantified for PA14 Δcsy4 or Δcsy4/ΔphrS before and after BCM treatment. Results are shown with mean ± SEM from three independent experiments. **P < 0.01, *P < 0.05, one-way ANOVA plus Tukey test
