Exonuclease definition

Exonucleases are enzymes that work by cleaving nucleotides one at a time from the end (exo) of a polynucleotide chain. This is possible by using a hydrolyzing reaction that breaks phosphodiester bonds at either the 3' or the 5', depending on the type of exonuclease. One example of this type of enzymes are Lambda exonuclease or RecJ exonuclease.

There are also some other enzymes that are not exonucleases but present exonuclease activity, such as the DNA polymerase.