Exonuclease

As exonuclease a is nuclease denotes that of its substrate (the nucleic acid - DNA and / or RNA ) per reaction cycle in each case a nucleic acid monomer splits off from the end of the molecule forth.

Successive reactions result in partial or complete degradation of the respective nucleic acid molecule starting from one end. This so-called exonucleolytic digestion leaves behind a shortened nucleic acid molecule and a monomer per reaction, while in endonucleolytic digestion an endonuclease creates two fragments.

Exonucleases are used, for example, as correction enzymes in DNA replication. In this way, incorrectly incorporated nucleotide bases are removed from them again. Another example is the T5 exonuclease .

See also

• Exoribonuclease (RNA)
• Deoxyribonuclease (DNA)

literature

• Cornel Mülhardt: The Experimenter: Molecular Biology / Genomics. Sixth edition. Spectrum Akademischer Verlag, Heidelberg 2008, ISBN 3-8274-2036-9 .
• J. Sambrook , T. Maniatis , DW Russel: Molecular cloning: a laboratory manual. 3rd edition (2001), Cold Spring Harbor Laboratory Press. ISBN 0-87969-577-3 .