Exonuclease that has both 3'-5' exoribonuclease and exodeoxyribonuclease activities, depending on the divalent metal cation used as cofactor (PubMed:29335528, PubMed:31127291). In presence of Mg(2+), only shows 3'-5' exoribonuclease activity, while it shows both exoribonuclease and exodeoxyribonuclease activities in presence of Mn(2+) (PubMed:29335528, PubMed:31127291). Acts as an exoribonuclease in mitochondrion, possibly by regulating ATP production and mitochondrial translation (PubMed:29335528). Also involved in the response to DNA damage (PubMed:26807646, PubMed:31255466). Acts as 3'-5' exodeoxyribonuclease for double-strand breaks resection and efficient homologous recombination (PubMed:20603073, PubMed:26807646). 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 (PubMed:26807646). 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 (PubMed:31255466). Exonucleolytic cleavage in the 3'- to 5'-direction to yield nucleoside 5'-phosphates. Divalent metal cations; Mg(2+) or Mn(2+) (PubMed:31127291). Acts as a 3'-5' exoribonuclease in presence of Mg(2+), while it has no 3'-5' exodeoxyribonuclease activity (PubMed:29335528, PubMed:31127291). Has both as a 3'-5' exoribonuclease and exodeoxyribonuclease activities in presence of Mn(2+) (PubMed:31127291). Homodimer (PubMed:31127291). Interacts with RBBP8, MRE11 and BRCA1 (PubMed:26807646). Mainly localizes to the mitochondrial outer membrane (PubMed:29599527, PubMed:31127291). May translocate to the nucleus in response to DNA damage; however mechanism that explain nuclear localization are unknown and require experimental evidences (PubMed:26807646). Recruited to replication forks following replication stress (PubMed:31255466). Belongs to the EXD2 family. Subcellular location is subject to discussion. Different publications report a mitochondrial localization (PubMed:29335528, PubMed:29599527, PubMed:31127291). According to some reports, tranlocates to the nucleus in response of DNA damage (PubMed:26807646, PubMed:31255466). However, according to another publication, DNA damage does not result in nuclear translocation (PubMed:31127291). Its precise localization in mitochondrion is also controversial (PubMed:29335528, PubMed:29599527, PubMed:31127291). Two different groups report a localization to the mitochondrial outer membrane, which is consistent with the presence of a N-terminal transmembrane region (PubMed:29599527, PubMed:31127291). In contrast, a publication reports localization to the mitochondrial matrix; protease accessibility used in this assay can however lead to misinterpretation if the target protein is unexpectedly resistant to proteases (PubMed:29335528). Mechanisms that explain its dual role in mitochondrion and nuclear DNA repair are unknown and additional evidences are needed to reconciliate these two apparently incompatible functions.