Figure 3. Alignment of the nucleotide sequence of the nad5-374 target editing site with other non-target editing sites. The nucleotides around the nad5-374 editing site (large bold C) show a very high content of U nucleotides especially in the presumed target window of PPR recognition between the nucleotides -4 to -25 or -30. Comparison with the most similar sequences preceding other editing sites (large bold C) accordingly selects for sites with U-rich upstream regions in Arabidopsis thaliana. Of the four most similar sequences aligned here, editing site nad2-842 is fully edited in the mef12-1 mutant and is a target of MEF10.17 Site nad5-676 is also not recognized by MEF12, but requires the MEF8 protein. Vice versa, MEF10 and MEF8 do not influence the MEF12 target site at nucleotide nad5-374.43 Differentiation between the different target sites should thus involve those nucleotides, which differ between the cis-recognition sequences. Nucleotides identical to the nad5-374 MEF12-target site are inversely shaded. Sequences are shown 5′ to 3′ from left to right.