Major transcript of the frameshifted coxII gene from trypanosome mitochondria contains four nucleotides that are not encoded in the DNA

Cell. 1986 Sep 12;46(6):819-26. doi: 10.1016/0092-8674(86)90063-2.


The mitochondrial cytochrome oxidase (cox) subunit II gene from trypanosomes contains a frameshift at amino acid 170. This gene is highly conserved in different trypanosome species, suggesting that it is functional. Sequence determination of coxII transcripts of T. brucei and C. fasciculata reveals four extra, reading frame-restoring nucleotides at the frameshift position that are not encoded in the DNA. Southern blot analysis of DNA of both trypanosome species failed to show the existence of a second version of the coxII gene. We conclude, therefore, that the extra nucleotides are added during or after transcription of the frameshift gene by an RNA-editing process.

MeSH terms

  • Animals
  • Base Sequence
  • Crithidia / genetics*
  • DNA, Mitochondrial / genetics*
  • Electron Transport Complex IV / genetics*
  • Endonucleases
  • Genes
  • Nucleic Acid Hybridization
  • RNA Processing, Post-Transcriptional
  • RNA, Messenger / genetics
  • Single-Strand Specific DNA and RNA Endonucleases
  • Trypanosoma brucei brucei / genetics*


  • DNA, Mitochondrial
  • RNA, Messenger
  • Electron Transport Complex IV
  • Endonucleases
  • Single-Strand Specific DNA and RNA Endonucleases