Probable component of the exosome 3'->5' exoribonuclease complex, a complex that degrades inherently unstable mRNAs containing AU-rich elements (AREs) within their 3'-untranslated regions. May form a homodimer separately from exosome complexes and function in DNA cleavage process. Binds double-stranded DNA (dsDNA) and single-stranded RNA (ssRNA), and possesses hydrolytic DNase and phosphorolytic RNase activities in vitro. Homodimer or monomer when reduced or oxidized, respectively. Component of the exosome core complex (Probable). Belongs to the RNase PH family.