Endo/exonuclease with nicking activity towards supercoiled DNA, a preference for single-stranded DNA and 5'-3' exonuclease activity. Homodimer. Ubiquitous. The active site contains 1 hydrated divalent metal cation that has only 1 direct interaction with the protein; all other interactions are via water molecules. Probably inactive since it lacks the active site. Probably inactive since it lacks the active site. Belongs to the DNA/RNA non-specific endonuclease family.