Mitochondrial DNA (mtDNA) polymerase γ has a 3′–5′ exonuclease proofreading activity. Here, the authors show it is required for creating ligatable ends during mtDNA replication, and inactivation of the activity in mice causes strand-specific nicks in DNA and the formation of linear mtDNA fragments.
- Bertil Macao
- Jay P. Uhler
- Maria Falkenberg