Mörl M, Schmelzer C
Institut für Genetik und Mikrobiologie, Universität München, Federal Republic of Germany.
Cell. 1990 Feb 23;60(4):629-36. doi: 10.1016/0092-8674(90)90666-3.
Group II intron bI1, the first intron of the COB gene in the mitochondria of S. cerevisiae, is able to self-splice in vitro with the basic pathway similar to nuclear pre-mRNA splicing. We show that incubation of the intron lariat with ligated exons bE1 and bE2 leads to a complete reversal of the splicing reaction. The integration of the intron into the ligated exons is correct; the reconstituted preRNA of the reverse reaction can undergo a self-splicing reaction anew. When incubated with a foreign RNA species bearing a sequence motif that is complementary to exon binding site 1, the lariat can integrate into this RNA with the position of insertion immediately downstream of this sequence. This result implies that transposition of group II introns on the RNA level by reversal of the splicing reaction is, in principle, conceivable.
第二组内含子bI1是酿酒酵母线粒体中COB基因的第一个内含子，能够在体外进行自我剪接，其基本途径类似于核前体mRNA剪接。我们发现，将内含子套索与连接的外显子bE1和bE2一起温育会导致剪接反应完全逆转。内含子整合到连接的外显子中是正确的；反向反应重构的前体RNA可以再次进行自我剪接反应。当与带有与外显子结合位点1互补的序列基序的外源RNA物种一起温育时，套索可以整合到该RNA中，插入位置紧接在该序列的下游。这一结果表明，通过剪接反应的逆转，第二组内含子在RNA水平上的转座原则上是可以想象的。
