Exonuclease that has both 3'-5' exoribonuclease and exodeoxyribonuclease activities, depending on the divalent metal cation used as cofactor (, ). In presence of Mg(2+), only shows 3'-5' exoribonuclease activity, while it shows both exoribonuclease and exodeoxyribonuclease activities in presence of Mn(2+) (, ). Acts as an exoribonuclease in mitochondrion, possibly by regulating ATP production and mitochondrial translation . Also involved in the response to DNA damage (, ). Acts as 3'-5' exodeoxyribonuclease for double-strand breaks resection and efficient homologous recombination (, ). Plays a key role in controlling the initial steps of chromosomal break repair, it is recruited to chromatin in a damage-dependent manner and functionally interacts with the MRN complex to accelerate resection through its 3'-5' exonuclease activity, which efficiently processes double-stranded DNA substrates containing nicks . Also involved in response to replicative stress: recruited to stalled forks and is required to stabilize and restart stalled replication forks by restraining excessive fork regression, thereby suppressing their degradation .
Subcellular locations: Mitochondrion outer membrane, Mitochondrion matrix, Nucleus, Chromosome
Mainly localizes to the mitochondrial outer membrane (, ). May translocate to the nucleus in response to DNA damage; however mechanism that explain nuclear localization are unknown and require experimental evidences . Recruited to replication forks following replication stress .