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. Exonucleolytic cleavage in the 3'- to 5'-direction to yield nucleoside 5'-phosphates. Divalent metal cations; Mg(2+) or Mn(2+). Acts as a 3'-5' exoribonuclease in presence of Mg(2+), while it has no 3'-5' exodeoxyribonuclease activity. Has both as a 3'-5' exoribonuclease and exodeoxyribonuclease activities in presence of Mn(2+). Homodimer. Interacts with RBBP8, MRE11 and BRCA1. 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. Belongs to the EXD2 family.