Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1953342 | Biochimie | 2006 | 7 Pages |
Abstract
RmInt1 is a mobile group II intron which interrupts ISRm2011-2, another mobile element from the bacterium Sinorhizobium meliloti. Ribozyme constructs derived from intron RmInt1 self-splice in vitro when incubated under permissive conditions, but the excised intron and ligated exons are largely replaced by unconventional products. These include a slightly shorter, 5â²-end truncated 3â² exon, truncated variants of the linear and lariat forms of the intron-3â² exon reaction intermediate, as well as presumably circular molecules derived from the latter. Two factors explain the abundance of these products: (i) nucleotides 5-11 of the 3â² exon (IBS1*) provide a better match to the EBS1 5â²-exon-binding site than the authentic IBS1 sequence in the 5â² exon; (ii) exon ligation is unusually inefficient, and especially so when the 5â² exon is truncated close to the second (IBS2) intron-binding site. We propose that reactions at the IBS1* site play a part in the regulation of the intron ISRm2011-2 host in vivo.
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Authors
MarÃa Costa, François Michel, MarÃa Dolores Molina-Sánchez, Francisco Martinez-Abarca, Nicolás Toro,