Escherichia coli cell division inhibitor DicF-RNA of the dicB operon. Evidence for its generation in vivo by transcription termination and by RNase III and RNase E-dependent processing

J Mol Biol. 1990 Apr 5;212(3):461-71. doi: 10.1016/0022-2836(90)90325-G.


We have established that the long non-coding intercistronic region of the dicB operon of Escherichia coli expresses a trans-acting division inhibitor specified by a region dicF, at most 65 nucleotides-long. The present study deals with the processing of dicBF operon mRNA in vivo, and identifies the dicF gene product as a 53 nucleotide RNA species. A sequence at the end of DicF resembles, and behaves as, a Rho-independent terminator, but further processing of readthrough transcripts, presumably by RNase III, followed by a limited 3' to 5' degradation, appears to generate additional DicF-RNA 3' ends. For the 5' end of DicF-RNA, our results show that a 190 nucleotide precursor DicF-RNA species is formed by cleavage at an RNase III site, while the 53 nucleotide minimal DicF-RNA is generated by further processing requiring the presence of an active form of RNase E in vivo. These data indicate that an untranslated product derived from an operon RNA can have a regulatory activity by affecting cell division.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Cell Division*
  • Endoribonucleases / metabolism*
  • Escherichia coli / genetics*
  • Escherichia coli Proteins*
  • Introns
  • Molecular Sequence Data
  • Mutation
  • Nucleic Acid Conformation
  • Operon
  • RNA Processing, Post-Transcriptional*
  • RNA, Bacterial / genetics*
  • RNA, Bacterial / metabolism
  • Ribonuclease III
  • Transcription, Genetic*


  • Escherichia coli Proteins
  • RNA, Bacterial
  • Endoribonucleases
  • Ribonuclease III
  • ribonuclease III, E coli
  • ribonuclease E