Exonuclease

A nuclease is referred to as an exonuclease, which cleaves a nucleic acid monomer in each of the forth end of the molecule from its substrate (DNA and / or RNA) per reaction cycle.

By successive reactions it is the partial or complete reduction of the particular nucleic acid molecule, starting from an end. This so-called exonucleolytic digestion leaves per reaction a truncated nucleic acid molecule and a monomer, while the endonucleolytic digestion by an endonuclease, two fragments are formed.

Exonucleases occur, for example as a correction enzymes involved in DNA replication. So incorrectly incorporated nucleotide bases of them are removed.

• Nuclease