Compilation and analysis of group II intron insertions in bacterial genomes: evidence for retroelement behavior.

ABSTRACT: Group II introns are novel genetic elements that have properties of both catalytic RNAs and retroelements. Initially identified in organellar genomes of plants and lower eukaryotes, group II introns are now being discovered in increasing numbers in bacterial genomes. Few of the newly sequenced bacterial introns are correctly identified or annotated by those who sequenced them. Here we have compiled and thoroughly analyzed group II introns and their fragments in bacterial DNA sequences reported to GenBank. Intron distribution in bacterial genomes differs markedly from the distribution in organellar genomes. Bacterial introns are not inserted into conserved genes, are often inserted outside of genes altogether and are frequently fragmented, suggesting a high rate of intron gain and loss. Som

SUBMITTER: Dai L 

PROVIDER: S-EPMC101233 | biostudies-literature | 2002 Mar

REPOSITORIES: biostudies-literature