RNA structure, not sequence, determines the 5' splice-site specificity of a group I intron

Proc Natl Acad Sci U S A. 1989 Oct;86(19):7402-6. doi: 10.1073/pnas.86.19.7402.


The group I self-splicing introns act at exon-intron junctions without recognizing a particular sequence. In order to understand splice-site selection, we have developed an assay system based on the Tetrahymena ribozyme to allow the study of numerous 5'-splice-site variants. Cleavage at the correct site requires formation of the correct secondary structure and occurs most efficiently within a 3-base-pair window centered on base pair 5 from the bottom of the P1 stem. Within this window the ribozyme recognizes and cleaves at a "wobble" base pair; the base pair above the cleavage site also influences splicing efficiency. The recognition of RNA structure rather than sequence explains the ability of these transposable introns to splice out of a variety of sequence contexts.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Composition
  • Base Sequence
  • Exons
  • Introns*
  • Kinetics
  • Molecular Sequence Data
  • Mutation
  • Nucleic Acid Conformation
  • Plasmids
  • RNA Splicing*
  • RNA, Catalytic
  • RNA, Ribosomal / genetics*
  • Tetrahymena / genetics*


  • RNA, Catalytic
  • RNA, Ribosomal