Multiple group II self-splicing introns in mobile DNA from Escherichia coli.
By PCR (polymerase chain reaction) amplification and cloning, we have identified four group II self-splicing introns encoding proteins related to reverse transcriptases in natural Escherichia coli isolates belonging to the ECOR collection. One intron, IntD, interrupts a DNA sequence virtually identical to that of the previously described IS3411 Insertion Sequence. A second intron, IntC, is located within an open reading frame that is closely related to a reading frame in the T-DNA of Agrobacterium tumefaciens. Finally, introns IntA and IntB are inserted at two distinct sites in one of the Rhs elements of E. coli. A comparison of their open reading frames shows that the two Rhs introns are more closely related to each other than to any other known group II intron: this suggests that transposition of group II introns may occur preferentially in cis, along the same piece of DNA.
Ferat
J L
JL
Centre de Génétique Moléculaire du CNRS, Laboratoire associé à l'Université Pierre-et-Marie-Curie, Gif-sur-Yvette, France.
Le Gouar
M
M
Michel
F
F
D004251:DNA Transposable Elements / Q000187:drug effects* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D066298:In Vitro Techniques; D007438:Introns / Q000235:genetics*; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D016337:RNA, Catalytic / Q000494:pharmacology*
D004251:DNA Transposable Elements; D016337:RNA, Catalytic