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An enzyme that catalyzes the splitting of nucleic acids to nucleotides, nucleosides, or the components of the latter.



a phosphodiesterase enzyme that splits nucleic acids into mononucleotides and oligonucleotides.

Nucleases are widely distributed in the cells of microorganisms, plants, and animals. These enzymes are especially abundant in pancreatic juice and in the saliva of mammals and man. A distinction is made between 3′ and 5′ nucleases, depending on whether the enzyme splits the phosphodiester bonds of the nucleic acid to form nucleotides that contain phosphoric acid residues on the 3’- or 5’-carbon of the carbohydrate fragment. The terminal mononucleotides are separated by exonucleases; nucleases that split bonds within the polynucleotide chain are called endonucleases. Ribonucleases and deoxyribonucleases are distinguished according to whether they split ribonucleic or deoxyribonucleic acids. Nonspecific nucleases are able to split chains of both types of acids.

Nucleases are proteins—usually basic—with a comparatively low molecular weight; for example, the pancreatic ribonuclease molecule consists of 124 amino-acid residues. The biological function of nucleases is to digest and split nucleic acids that are foreign to the organism, for example, nucleic acids of invasive viruses. This is the rationale for using nucleases to treat certain viral diseases. Nucleases participate in the repair of deoxyribonucleic acid (DNA) by eliminating the fragmented portions of the DNA molecule from the polynucleotide chain. Nucleases also appear to play a major role in regulating the synthesis and decomposition of nucleic acids in cells. A nuclease enzyme can be used in laboratories to free preparations from a specific nucleic acid, to determine the structure of nucleic acids, and to study the mechanism of nucleic acid decomposition and synthesis.


Shapot, V. S. Nukleazy. Moscow, 1968.


References in periodicals archive ?
Use of a universal reporter system removes the need for the expensive, allele-specific, fluorescently labeled probes required for 5' nuclease assays.
Heat treatment of soil DNA at 65 degC for 20 minutes was carried out to inactivate nuclease enzymes.
It employs its own RNA guided nuclease proteins to cleave the specific target site [17].
With the development of dCas9 (dead Cas9) in which Cas9 nuclease activity is mutated and is attached with Fokl.
ZFNs, transcription activator-like effector nucleases (TALENs), and clusteredregularly interspersed short palindromic repeats (CRISPR) technologies are transformative tools that have the potential to revolutionize biological research.
It is not excluded that this activity is related to the manifestation of other forms of nuclease activity, that is why we studied the enzymatic activities of these protein extracts in the presence of [Mn.
Site-directed mutagenesis of the conserved residues in H-N-H motif in Usp showed that H-N-H motif was important for DNase activity of Usp, indicating that Usp is a member of H-N-H nuclease superfamily.
They used the same nuclease to zero in on an undamaged section of the CCR5 receptor's DNA.
Recently, the presence of a mitochondrial nuclease, which migrates to the nucleus in response to apoptotic stimuli (8,9) has been identified, both in species of Trypanosoma (T.
In this research, commercially available anti-oxidants will be employed to examine the inhibitory effects of methionine oxidation upon the stability of staphylococcal nuclease, a well-characterized model protein.
All of these genes are potential targets for our ZFP technology, and it is therefore particularly exciting for all of us to have already achieved significant milestones validating the applications of our nuclease technology in plant agriculture.