Universal Code Equivalent of a Yeast Mitochondrial lntron Reading Frame Is Expressed into E. coli as a Specific Double Strand Endonuclease

Laurence Colleaux (1) , L d'Auriol (2) , M Betermiert (3, 4) , G Cottarel (4) , : A Jacquier (4) , F. Galibert (5) , B Dujorv (4)

1 IMAGINE - U1163 - Imagine - Institut des maladies génétiques
2 Laboratoire d'Hématologie Expérimentale
3 CRBGC - Centre de Recherche de Biochimie et de Génétique Cellulaire
4 CGM - Centre de génétique moléculaire
5 LBBE - Laboratoire de Biométrie et Biologie Evolutive - UMR 5558

The intron of the mitochondrial21S rRNA gene of Sac-charomyces cerevisiae (rl intron) possesses a 235 codon long internal open reading frame (rl ORF) whose translation product determines the duplicative transposition of that intron during crosses between intron-plus strains (omega+) and intron-minus ones (omega-). Using site-directed mutagenesis, we have constructed a universal code equivalent of the rl ORF that, under appropriate promoter control, allows the overexpression in E. coli of a protein identical to the mitochondrial intron encoded "transposase". This protein exhibits a double strand endonuclease activity specific for the omega-site. This finding demonstrates , for the first time, the enzymatic activity of an intron encoded protein whose function is to promote the spreading of that intron by generating double strand breaks at a specific sequence within a gene.

Domaines: Génétique humaine

Laurence Colleaux, L d'Auriol, M Betermiert, G Cottarel, : A Jacquier, et al.. Universal Code Equivalent of a Yeast Mitochondrial lntron Reading Frame Is Expressed into E. coli as a Specific Double Strand Endonuclease. Cell, 1986, 44, pp.521 - 533. ⟨hal-02044365⟩