Table 2.
RNA editing affects mitochondrial mRNAs at very different rates
| Gene | Number of C/U editing sites in ORFs (N) | Size of the coding region, kb (S) | Editing frequency N/S (no. sites/kb) | ∑N/∑S |
|---|---|---|---|---|
| nad1 | 24 | 0.973 | 24.7 | Complex I ORFs 20.00 |
| nad2 | 31 | 1.495 | 20.7 | |
| nad3 | 12 | 0.359 | 33.4 | |
| nad4 | 32 | 1.484 | 21.6 | |
| nad4L | 9 | 0.302 | 29.8 | |
| nad5 | 27 | 2.005 | 13.5 | |
| nad6 | 10 | 0.617 | 16.2 | |
| nad7 | 28 | 1.180 | 23.7 | |
| nad9 | 7 | 0.572 | 12.2 | |
| Ψsdh4 | 5 | 0.285 | 17.5 | Complex II ORF 17.5 |
| cob | 7 | 1.181 | 5.9 | Complex III ORF 5.9 |
| cox1 | 0 | 1.583 | 0 | Complex IV ORFs 7.3 |
| cox2 | 15 | 0.781 | 19.2 | |
| cox3 | 8 | 0.797 | 10.0 | |
| atp1 | 5 | 1.523 | 3.3 | Complex V ORFs 2.9 |
| atp6-1 | 1 | 1.157 | 0.9 | |
| atp8 (orfB) | 0 | 0.476 | 0 | |
| atp9 | 4 | 0.257 | 15.6 | |
| ccb2 | 39 | 0.620 | 62.9 | Cytochrome c biogenesis ORFs 26.0 |
| ccb3 | 28 | 0.770 | 36.0 | |
| ccb6c | 16 | 1.357 | 11.8 | |
| ccb6n1 | 22 | 1.148 | 19.2 | |
| ccb6n2 | 12 | 0.611 | 19.6 | |
| rpl2 | 1 | 0.923 | 1.1 | Ribosomal protein ORFs 9.3 |
| rpl5 | 10 | 0.557 | 17.9 | |
| rpl16 | 8 | 0.539 | 14.8 | |
| rps3 | 10 | 1.669 | 6.0 | |
| rps4 | 15 | 1.088 | 13.8 | |
| rps7 | 0 | 0.446 | 0 | |
| rps12 | 8 | 0.377 | 21.2 | |
| Ψrps14 | 1 | 0.292 | 3.4 | |
| Ψrps19 | 0 | 0.116 | 0 | |
| mtt2 (orfX) | 24 | 0.860 | 27.9 | Not applicable |
| orf25 | 8 | 0.578 | 13.8 | |
| matR | 9 | 2.018 | 4.4 | |
| orf240a | 1 | 0.720 | 1.4 | |
| orf110c | 4 | 0.330 | 12.1 |
Data for individual mRNA species previously analyzed have been integrated. These include editing sites for nad2 and rps4 (13), nad4L and orf25 (22), nad5 exons d and e (23), cob, rpl5, and Yrps14 (24), orfX (25), and for ccb6n1 and matR (accession nos. X978254 and X98300, respectively). Cytochrome c biogenesis genes (ccb genes) are shown with new gene names; ccb2 is ccb206 (ccmB in Escherichia coli), ccb3 is ccb256 (ccmC in E. coli), ccb6n1 is ccb382, ccb6n2 is ccb203 and ccb6c is ccb452 (ccmF in E. coli, two genes corresponding to the N-terminal part and one gene corresponding to the C-terminal part, respectively).