Parasite mitochondrial DNA (mtDNA)

Parasite mitochondrial DNA (mtDNA) is the extrachromosomal genetic material found within the mitochondria of various parasitic protozoa, including those responsible for malaria (Plasmodium spp.) and kinetoplastid diseases (Trypanosoma and Leishmania spp.). In Plasmodium, the mtDNA is a compact 6-kb genome encoding only three proteins—cytochrome b and subunits I and III of cytochrome c oxidase—along with fragmented ribosomal RNAs (PMID: 8016611). In kinetoplastids, the mtDNA is uniquely organized into a massive network of catenated circular DNA molecules called kinetoplast DNA (kDNA), consisting of maxicircles encoding respiratory genes and minicircles encoding guide RNAs for RNA editing (PMID: 7761212). Because these parasites depend on the mitochondrial electron transport chain for survival, the mtDNA is a vital therapeutic target. Drugs like pentamidine and diminazene target the kDNA by binding to its minor groove, causing genome loss and parasite death (PMID: 7525167). Additionally, mutations in the mtDNA-encoded cytochrome b gene are the primary mechanism of resistance to drugs like atovaquone (PMID: 12832615). The distinct structural features of parasite mtDNA compared to human mtDNA allow for selective pharmacological intervention, though potential host toxicity remains a concern.

Other names

Mitochondrial genomeKinetoplast DNAkDNAChondriomeExtrachromosomal DNA

Drugs targeting parasite mtDNA typically act through minor groove binding, intercalation, or inhibition of mitochondrial topoisomerases, leading to the degradation or loss of the mitochondrial genome and subsequent respiratory failure (PMID: 7761212, 7525167).