A 5'-terminal stem-loop structure can stabilize mRNA in Escherichia coli

Genes Dev. 1992 Jan;6(1):135-48. doi: 10.1101/gad.6.1.135.

Abstract

The 5'-untranslated region of the long-lived Escherichia coli ompA transcript functions as an mRNA stabilizer capable of prolonging the lifetime in E. coli of a number of heterologous messages to which it is fused. To elucidate the structural basis of differential mRNA stability in bacteria, the domains of the ompA 5'-untranslated region that allow it to protect mRNA from degradation have been identified by mutational analysis. The presence of a stem-loop no more than 2-4 nucleotides from the extreme 5' terminus of this RNA segment is crucial to its stabilizing influence, whereas the sequence of the stem-loop is relatively unimportant. The potential to form a hairpin very close to the 5' end is a feature common to a number of stable prokaryotic messages. Moreover, the lifetime of a normally labile message (bla mRNA) can be prolonged in E. coli by adding a simple hairpin structure at its 5' terminus. Accelerated degradation of ompA mRNA in the absence of a 5'-terminal stem-loop appears to start downstream of the 5' end. We propose that E. coli messages beginning with a single-stranded RNA segment of significant length are preferentially targeted by a degradative ribonuclease that interacts with the mRNA 5' terminus before cleaving internally at one or more distal sites.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Outer Membrane Proteins / genetics
  • Base Composition
  • Base Sequence
  • DNA Mutational Analysis
  • Escherichia coli / genetics
  • Escherichia coli / metabolism*
  • Gene Expression Regulation, Bacterial / genetics*
  • Kinetics
  • Methylation
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Plasmids / genetics
  • RNA, Bacterial / chemistry
  • RNA, Bacterial / metabolism
  • RNA, Messenger / chemistry
  • RNA, Messenger / metabolism*
  • Substrate Specificity

Substances

  • Bacterial Outer Membrane Proteins
  • RNA, Bacterial
  • RNA, Messenger