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Article: Nucleases
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- Genetics
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CopyrightCOPYRIGHT 2003 The Gale Group Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Nucleases
DNA and RNA are
polymers
made by linking together smaller units called
nucleotides
. Nucleases are enzymes that break the chemical bonds, called
phosphodiester bonds
, that hold the nucleotides of DNA or RNA polymers together. Enzymes that cleave the phosphodiester bonds of DNA are called deoxyribonucleases, and enzymes that cleave the phosphodiester bonds of RNA are called ribonucleases.
Nucleases can be divided into two classes, exonucleases and endonucleases, based on the positions of the cleaved bonds within the DNA or RNA polymers. The exonucleases are involved in trimming the ends of RNA and DNA polymers, cleaving the last phosphodiester bond in a chain. This cleavage ...