The mitochondrial DNA polymerase gamma degrades linear DNA fragments precluding the formation of deletions

Nadee Nissanka, Sandra R. Bacman, Melanie J. Plastini, Carlos T. Moraes

Research output: Contribution to journalArticle

21 Scopus citations


Double-strand breaks in the mitochondrial DNA (mtDNA) result in the formation of linear fragments that are rapidly degraded. However, the identity of the nuclease(s) performing this function is not known. We found that the exonuclease function of the mtDNA polymerase gamma (POLG) is required for this rapid degradation of mtDNA fragments. POLG is recruited to linearized DNA fragments in an origin of replication-independent manner. Moreover, in the absence of POLG exonuclease activity, the prolonged existence of mtDNA linear fragments leads to increased levels of mtDNA deletions, which have been previously identified in the mutator mouse, patients with POLG mutations and normal aging.

Original languageEnglish (US)
Article number2491
JournalNature communications
Issue number1
StatePublished - Dec 1 2018


ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)

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