Table 1.
Mitochondrial DNA-encoded genes and their functions
| (1) Coupled electron transport–oxidative phosphorylation (ATP synthesis) | |
| Complex I (NADH:ubiquinone oxidoreductase) | nad1, 2, 3, 4, 4L, 5, 6, 7, 8, 9, 10, 11 |
| Complex II (succinate:ubiquinone oxidoreductase) | sdh 2, 3, 4 |
| Complex III (ubiquinol:cytochrome c oxidoreductase) | cob |
| Complex IV (cytochrome c:O2 oxidoreductase) | cox1, 2, 3 |
| Complex V (F1F0 ATP synthase) | atp1, 3, 4,a 6, 8,b 9 |
| (2) Translation | |
| Ribosomal RNAs | rnl (LSU), rns (SSU), rrr5 (5S) |
| Ribosomal proteins | |
| Small subunit (SSU) | rps1, 2, 3, 4, 7, 8, 10, 11, 12, 13, 14, 19 |
| Large subunit (LSU) | rpl1, 2, 5, 6, 10, 11, 14, 16, 18, 19, 20, 27, 31, 32, 34 |
| Transfer RNAs | trnA, C, … W, Y |
| Elongation factor | tufA |
| tm RNA (unstalling of translation) | ssrA |
| (3) Transcription | |
| Core RNA polymerase | rpoA, B, C |
| Sigma factor | rpoD |
| (4) RNA processing | |
| RNase P RNA (5′ tRNA processing) | rnpB |
| (5) Protein import | |
| ABC transporter | ccmA (yejV), ccmB (yejW) |
| Heme delivery | ccmC (yejU) |
| SecY-type transporter | secY |
| Sec-independent transporter | tatA (mttA)c, tatC (mttB) |
| (6) Protein maturation | |
| Cytochrome oxidase assembly | cox11 |
| Heme c maturation | ccmF (yejR) |
A subset of the genes is encoded in the mtDNA of various eukaryotes; for example, those in bold are found in human and other mammalian mitochondrial genomes. Only the most ancestral (gene-rich) mtDNAs, for example, those of jakobid flagellates such as Reclinomonas americana, encode all or almost all of this gene set. Rare genes of uncertain origin and function include dpo (plasmid-derived DNA polymerase), rpo (plasmid-derived RNA polymerase), rtl (reverse transcriptase), mutS (DNA repair), and dam (methyltransferase). See Gray et al. (2004) for details.
aAlso referred to as orf25 and ymf39 (Burger et al. 2003b).
bAlso referred to as orfB and ymf19 (Gray et al. 1998).
cJacob et al. (2004).