A novel small regulatory RNA enhances cell motility in enterohemorrhagic Escherichia coli

J Gen Appl Microbiol. 2014;60(1):44-50. doi: 10.2323/jgam.60.44.


Small regulatory RNAs (sRNAs) are conserved among a wide range of bacteria. They modulate the translational efficiency of target mRNAs through base-pairing with the help of RNA chaperone Hfq. The present study identified a novel sRNA, Esr41 (enterohemorrhagic Escherichia coli O157 small RNA #41), from an intergenic region of an enterohemorrhagic E. coli (EHEC) O157:H7 Sakai-specific sequence that is not present in the nonpathogenic E. coli K-12. Esr41 was detected as an RNA molecule approximately 70 nucleotides long with a 3' GC-rich palindrome sequence followed by a long poly(U), which is a characteristic of rho-independent terminators and is also a structural feature required for the action of Hfq. EHEC O157 harboring a multicopy plasmid carrying the esr41 gene increased cell motility and the expression of fliC, a gene encoding a major flagellar component. These results indicate that Esr41 stimulates fliC expression in EHEC O157. Furthermore, the increase in cell motility induced by Esr41 was also observed in the E. coli K-12, suggesting that target genes controlled by Esr41 are present in both EHEC O157 and K-12.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Escherichia coli K12 / genetics
  • Escherichia coli O157 / genetics*
  • Escherichia coli O157 / pathogenicity
  • Escherichia coli O157 / physiology*
  • Escherichia coli Proteins / genetics
  • Flagellin
  • Gene Expression
  • Genes, Bacterial
  • Molecular Sequence Data
  • Movement / physiology
  • Plasmids / genetics
  • RNA, Bacterial / genetics*
  • Regulatory Sequences, Ribonucleic Acid*
  • Species Specificity


  • Escherichia coli Proteins
  • FliC protein, E coli
  • RNA, Bacterial
  • Regulatory Sequences, Ribonucleic Acid
  • Flagellin