EMBO Journal, 02 May 2016, Vol.35(9), pp.991-1011
The molecular roles of many ‐binding proteins in bacterial post‐transcriptional gene regulation are not well understood. Approaches combining crosslinking with deep sequencing (‐seq) have begun to revolutionize the transcriptome‐wide mapping of eukaryotic ‐binding protein target sites. We have applied ‐seq to chart the target landscape of two major bacterial post‐transcriptional regulators, Hfq and CsrA, in the model pathogen Typhimurium. By detecting binding sites at single‐nucleotide resolution, we identify preferences and structural constraints of Hfq and CsrA during their interactions with hundreds of cellular transcripts. This reveals 3′‐located Rho‐independent terminators as a universal motif involved in Hfq– interactions. Additionally, Hfq preferentially binds 5′ to ‐target sites in s, and 3′ to seed sequences in s, reflecting a simple logic in how Hfq facilitates – interactions. Importantly, global knowledge of Hfq sites significantly improves ‐target predictions. CsrA binds sequences in apical loops and targets many virulence s. Overall, our generic ‐seq approach will bring new insights into post‐transcriptional gene regulation by ‐binding proteins in diverse bacterial species. A new pipeline for ‐seq in maps global –protein interactions and offers a tool for improved understanding of post‐transcriptional control in bacteria. Transcriptome‐wide mapping of Hfq and CsrA target sites by CLIP‐seq. Rho‐independent terminators comprise a general Hfq‐binding motif. Hfq binds 5′ to sRNA‐binding sites in mRNA targets and 3′ to seed sequences in cognate the sRNAs. CsrA preferentially recognizes AUGGA sequences present in loops of hairpin structures. CsrA binds and regulates many mRNAs encoding virulence factors. A new pipeline for CLIP‐seq in maps global RNA–protein interactions and offers a tool for improved understanding of post‐transcriptional control in bacteria.
Clip ; Csra ; Hfq ; Non‐Coding Rna ; Peak Calling ; Post‐Transcriptional Control ; Small Rna ; Terminator ; Translation