Retrotransposition of a yeast group II intron occurs by reverse splicing directly into ectopic DNA sites

Citation
L. Dickson et al., Retrotransposition of a yeast group II intron occurs by reverse splicing directly into ectopic DNA sites, P NAS US, 98(23), 2001, pp. 13207-13212
Citations number
29
Categorie Soggetti
Multidisciplinary
Journal title
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
ISSN journal
00278424 → ACNP
Volume
98
Issue
23
Year of publication
2001
Pages
13207 - 13212
Database
ISI
SICI code
0027-8424(20011106)98:23<13207:ROAYGI>2.0.ZU;2-T
Abstract
Group II introns, the presumed ancestors of nuclear pre-mRNA introns, are s ite-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 bee n proposed for group II intron transposition, one involving reverse splicin g of the intron RNA directly into an ectopic DNA site, and the other involv ing reverse splicing into a site in RNA followed by reverse transcription a nd integration of the resulting cDNA by homologous recombination. Here, by using an "inverted-site" strategy, we show that the yeast mtDNA group II in tron all retrotransposes by reverse splicing directly into an ectopic DNA s ite. This same mechanism could account for other previously described ectop ic transposition events in fungi and bacteria and may have contributed to t he dispersal of group II introns into different genes.