SRA

The Gram-negative pathogen Pasteurella multocida is responsible for many important animal diseases. While a number of P. multocida virulence factors have been identified, very little is known about how gene expression and protein production is regulated in this organism. One mechanism by which bacteria regulate transcript abundance and protein production is riboregulation, which involves the interaction of a small RNA (sRNA) with a target mRNA to alter transcript stability and/or translational efficiency. This interaction often requires stabilization by a ribosome binding protein such as ProQ or Hfq. In E. coli and other species, ProQ has been shown to play a critical role in stabilizing sRNA-mRNA interactions and preferentially binds to 3' stem-loop regions of the mRNA transcripts, characteristic of intrinsic transcriptional terminators. The aim of this study was to determine the role of ProQ riboregulation in P. multocida and identify the RNA regions to which it binds. We assessed differentially expressed transcripts in a proQ mutant and identified sites of direct ProQ-RNA interaction using in vivo UV-crosslinking and analysis of cDNA (CRAC). These analyses demonstrated that ProQ binds to, and stabilises, ProQ-dependant sRNAs and transfer RNAs in P. multocida via adenosine enriched, highly structured sequences. The binding of ProQ to two RNA molecules was characterised and showed that ProQ bound within the coding sequence of the uncharacterized PmVP161_1121 and within the 3' region of the sRNA Prrc13. Overall design: We report the transcriptional changes caused by the lack or overexpression of the ProQ protein RNA-seq comparing wild-type, proQ mutant and complemented mutant strains of P. multocida