Stabilization of Clostridium perfringens collagenase mRNA by VR-RNA-dependent cleavage in 5' leader sequence

Mol Microbiol. 2010 Sep;77(6):1416-28. doi: 10.1111/j.1365-2958.2010.07258.x. Epub 2010 Jun 23.


The small RNA (sRNA), VR-RNA that is directly regulated by the VirR/VirS two-component system, regulates many genes including toxin genes such as collagenase (colA) and phospholipase C (plc) in Clostridium perfringens. Although the VR-RNA 3' region is sufficient to regulate the colA and plc genes, the molecular mechanism of toxin gene regulation by VR-RNA remains unclear. Here, we found that colA mRNA is cleaved at position -79 and -78 from the A of the first codon (ATG) in the presence of VR-RNA. The processed transcripts were stable compared with longer intact transcripts. On the other hand, colA mRNA was labile in a VR-RNA-deficient strain, and processed transcripts were undetectable. The stability and processing of colA mRNA were restored by transformation of the 3' region of VR-RNA-expression vector. The 3' region of VR-RNA and colA mRNA had significant complementation and interacted in vitro. These results show that VR-RNA base pairs with colA mRNA and induces cleavage in the 5' untranslated region (UTR) of colA mRNA, which leads to the stabilization of colA mRNA and the activation of colA expression.

MeSH terms

  • 5' Untranslated Regions*
  • Bacterial Proteins / genetics*
  • Base Sequence
  • Clostridium perfringens / enzymology
  • Clostridium perfringens / genetics*
  • Gene Expression Regulation, Bacterial
  • Microbial Collagenase / genetics*
  • Molecular Sequence Data
  • Mutation
  • Nucleic Acid Conformation
  • Promoter Regions, Genetic
  • RNA Processing, Post-Transcriptional*
  • RNA Stability*
  • RNA, Bacterial / metabolism


  • 5' Untranslated Regions
  • Bacterial Proteins
  • RNA, Bacterial
  • Microbial Collagenase
  • kappa-toxin, Clostridium perfringens