Antagonistic signals within the COX2 mRNA coding sequence control its translation in Saccharomyces cerevisiae mitochondria

The positive element encoded within the mRNA specifying the pre-Cox2p leader peptide antagonizes translational inhibition by codons 15–25. Starting with cox2(1,15–91)::ARG8^m (Bonnefoy et al. 2001) and cox2(1,15–25,89–91)::ARG8^m, as diagrammed at the top of the figure, alleles were created that reintroduce codons 2–14, which encode the full leader peptide (“+2–14”); codons 2–6, which encode much of the positive element (“+2–6”; Bonnefoy et al. 2001); or a derivative of codons 2–6 in which the mRNA sequence has been altered, which leaves the positive element nonfunctional (“+2–6*”; Bonnefoy et al. 2001). ARG8^m, COX2 codons, and deleted regions are diagrammed as in Figure 1. Strains shown, from top to bottom: NB120, EHW155, NB43, EHW380, NB135, EHW383, NB179, and EHW384 (Table 1).