Destabilizing effect of an rRNA stem-loop on an attenuator hairpin in the 5' exon of the Tetrahymena pre-rRNA

Yong Cao, Sarah A. Woodson

Research output: Contribution to journalArticle


Self-splicing of the Tetrahymena group I intron is attenuated by an rRNA stem-loop in the 5' exon, which competes with formation of the P1 splice site helix. The equilibrium between the P1 and P(-1) stem-loops is influenced by rRNA sequences upstream and downstream of the intron. To investigate the mechanism of this conformational switch, internal deletions and point mutations were introduced in the second rRNA stem-loop upstream of the 5' splice site. Nuclease protection, native gel electrophoresis, and self- splicing results show that this helix is important for maintaining self- splicing activity. Co-axial base stacking of adjacent helices in the 5' exon is proposed to enable exchange between inactive and active conformations of the pre-rRNA.

Original languageEnglish (US)
Pages (from-to)901-914
Number of pages14
Issue number8
StatePublished - Aug 1 1998



  • Group I intron
  • RNA structure
  • Self-splicing

ASJC Scopus subject areas

  • Molecular Biology

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