Direct repeats found in the vicinity of intron splice sites.

ABSTRACT: Four main classes of introns (group I, group II, spliceosomal, and archaeal) have been reported for all major types of RNA from nuclei and organelles of a wide range of taxa. When and how introns inserted within the genic regions of genomes, however, is often unclear. Introns were examined from Archaea, Bacteria, and Eukarya. Up to 80 bp surrounding each of the 5' and 3' intron/exon borders were compared to search for direct repeats (DRs). For each of the 213 introns examined, DNA sequence analysis revealed DRs at or near the intron/exon borders, ranging from 4 to 30 bp in length, with a mean of 11.4 bp. More than 80% of the repeats were within 10 bp of the intron/exon borders. The numbers of DRs 6-30 bp in length were greater than expected by chance. When a DNA segment moves into a new ge

SUBMITTER: Rogers SO 

PROVIDER: S-EPMC11782384 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature