The spread of LAGLIDADG homing endonuclease genes in rDNA

Research output: Contribution to journalArticlepeer-review

41 Scopus citations


Group I introns that encode homing endonuclease genes (HEGs) are highly invasive genetic elements. Their movement into a homologous position in an intron-less allele is termed homing. Although the mechanism of homing is well understood, the evolutionary relationship between HEGs and their intron partners remains unclear. Here we have focused on the largest family of HEGs (encoding the protein motif, LAGLIDADG) to understand how HEGs and introns move in rDNA. Our analysis shows the phylogenetic clustering of HEGs that encode a single copy of the LAGLIDADG motif in neighboring, but often evolutionarily distantly related, group I introns. These endonucleases appear to have inserted into existing introns independent of ribozymes. In contrast, our data support a common evolutionary history for a large family of heterologous introns that encode HEGs with a duplicated LAGLIDADG motif. This finding suggests that intron/double-motif HEG elements can move into heterologous sites as a unit. Our data also suggest that a subset of the double-motif HEGs in rDNA originated from the duplication and fusion of a single-motif HEG encoded by present-day ribozymes in LSU rDNA.

Original languageEnglish (US)
Pages (from-to)2049-2057
Number of pages9
JournalNucleic acids research
Issue number6
StatePublished - 2004
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Genetics

Fingerprint Dive into the research topics of 'The spread of LAGLIDADG homing endonuclease genes in rDNA'. Together they form a unique fingerprint.

Cite this