Fig. 7.

PhrS-mediated anti-termination in CRISPR loci of multiple types CRISPR-Cas systems is a general phenomenon. a IntaRNA (Freiburg RNA tools) prediction of PhrS sRNA interaction with 5ʹUTR of CRISPR locus in multiple types CRISPR-Cas system. b CRISPR-lacZ activity for multiple types CRISPR-Cas system in WT or ΔphrS strain with or without BCM. c CRISPR-lacZ activity for multiple types CRISPR-Cas system in WT without PhrS overexpression, after PhrS overexpression. d Proposed model of PhrS-mediated regulation of CRISPR-Cas adaptive immunity. Bacterial small RNA PhrS inhibits the Rho-dependent termination to promote the expression of CRISPR loci, expanding function of sRNA in activating CRISPR-Cas adaptive immunity. Results are shown with mean ± SEM from three independent experiments. **P < 0.01, *P < 0.05, one-way ANOVA plus Tukey test