2001/10/30 by Lorna M. Dickson, Hon-Ren Huang, Lu Liu +3 · 1 citation
Biochemistry, Genetics and Molecular Biology · #RNA and protein synthesis mechanisms #RNA Research and Splicing #RNA modifications and cancer
paper · doi:10.1073/pnas.231494498
openalex publication_date 2001/10/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Group II introns, the presumed ancestors of nuclear pre-mRNA introns, are site-specific retroelements. In addition to "homing" to unoccupied sites in intronless alleles, group II introns transpose at low frequency to ectopic sites that resemble the normal homing site. Two general mechanisms have been proposed for group II intron transposition, one involving reverse splicing of the intron RNA directly into an ectopic DNA site, and the other involving reverse splicing into a site in RNA followed by reverse transcription and integration of the resulting cDNA by homologous recombination. Here, by using an "inverted-site" strategy, we show that the yeast mtDNA group II intron aI1 retrotransposes by reverse splicing directly into an ectopic DNA site. This same mechanism could account for other previously described ectopic transposition events in fungi and bacteria and may have contributed to the dispersal of group II introns into different genes.