This Article Full Text Full Text (PDF) Supplemental material Other Versions of this Article: JB.00234-07v1 189/14/5293    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nord, D. Articles by Sjöberg, B.-M. Search for Related Content PubMed PubMed Citation Articles by Nord, D. Articles by Sjöberg, B.-M.

A Functional Homing Endonuclease in the Bacillus anthracis nrdE Group I Intron ^,

David Nord, Eduard Torrents, and Britt-Marie Sjöberg^*

Department of Molecular Biology and Functional Genomics, Stockholm University, SE-10691 Stockholm, Sweden

Received 12 February 2007/ Accepted 25 April 2007

The essential Bacillus anthracis nrdE gene carries a self-splicing group I intron with a putative homing endonuclease belonging to the GIY-YIG family. Here, we show that the nrdE pre-mRNA is spliced and that the homing endonuclease cleaves an intronless nrdE gene 5 nucleotides (nt) upstream of the intron insertion site, producing 2-nt 3' extensions. We also show that the sequence required for efficient cleavage spans at least 4 bp upstream and 31 bp downstream of the cleaved coding strand. The position of the recognition sequence in relation to the cleavage position is as expected for a GIY-YIG homing endonuclease. Interestingly, nrdE genes from several other Bacillaceae were also susceptible to cleavage, with those of Bacillus cereus, Staphylococcus epidermidis (nrdE1), B. anthracis, and Bacillus thuringiensis serovar konkukian being better substrates than those of Bacillus subtilis, Bacillus lichenformis, and S. epidermidis (nrdE2). On the other hand, nrdE genes from Lactococcus lactis, Escherichia coli, Salmonella enterica serovar Typhimurium, and Corynebacterium ammoniagenes were not cleaved. Intervening sequences (IVSs) residing in protein-coding genes are often found in enzymes involved in DNA metabolism, and the ribonucleotide reductase nrdE gene is a frequent target for self-splicing IVSs. A comparison of nrdE genes from seven gram-positive low-G+C bacteria, two bacteriophages, and Nocardia farcinica showed five different insertion sites for self-splicing IVSs within the coding region of the nrdE gene.

Published ahead of print on 11 May 2007.

Supplemental material for this article may be found at http://jb.asm.org/.

Present address: Institute for Bioengineering of Catalonia (IBEC) and Microbiology Department, Biology Faculty, Avinguda Diagonal 645, ES-08028 Barcelona, Spain.

This article has been cited by other articles:

• Tourasse, N. J., Kolsto, A.-B. (2008). Survey of group I and group II introns in 29 sequenced genomes of the Bacillus cereus group: insights into their spread and evolution. Nucleic Acids Res 0: gkn372v1-gkn372 [Abstract] [Full Text]  
• Nord, D., Sjoberg, B.-M. (2008). Unconventional GIY-YIG homing endonuclease encoded in group I introns in closely related strains of the Bacillus cereus group. Nucleic Acids Res 36: 300-310 [Abstract] [Full Text]