Mitochondrial DNA replication machinery (mtDNA replication machinery)

The mitochondrial DNA (mtDNA) replication machinery, also known as the mitochondrial replisome, is a specialized protein complex responsible for the duplication and maintenance of the mitochondrial genome (PMID: 16352715). The core components of this machinery include the heterotrimeric DNA polymerase gamma (POLG), the hexameric Twinkle DNA helicase (TWNK), and the mitochondrial single-stranded DNA-binding protein (SSBP1) (UniProt: P54098, Q96RR1, Q04837). This system is essential for cellular energy production, as mtDNA encodes 13 critical subunits of the oxidative phosphorylation system (PMID: 27694354). While not typically a primary therapeutic target for activation, it is a major site of off-target toxicity for nucleoside reverse transcriptase inhibitors (NRTIs) used in HIV treatment, which can inhibit POLG and lead to mtDNA depletion (PMID: 11478370). Emerging research also explores the intentional inhibition of this machinery as a strategy to treat certain cancers that exhibit high dependency on mitochondrial function (PMID: 30143515). Mutations in the genes encoding these proteins are linked to a spectrum of mitochondrial diseases, such as Alpers-Huttenlocher syndrome and progressive external ophthalmoplegia (PMID: 15505000).

Other names

Mitochondrial replisomemtDNA replisomeMitochondrial DNA polymerase gamma complexPOLG-TWNK-SSBP1 complex

Inhibition of DNA polymerase gamma (POLG) by nucleoside analogs, leading to DNA chain termination and depletion of mitochondrial DNA (PMID: 16352715).