DNA replication, recombination and repair, all of which are necessary for genome stability, require the presence of exonucleases (1). In DNA replication, these enzymes are involved in the processing of Okazaki fragments, whereas in DNA repair, they function to excise damaged DNA fragments and correct recombinational mismatches (2). Exonucleases involved in these processes include DNA polymerases, including DNA pol ∂ and é. DNA pol ∂ consists of two subunits, p125 which interacts direc