Micrococcal nuclease

Micrococcal Nuclease (S7 Nuclease) is an endo-exonuclease that preferentially digests single-stranded nucleic acids.The rate of cleavage is 30 times greater at the 5' side of A or T than at G or C and results in the production of mononucleotides and oligonucleotides with terminal 3'-phosphates. The enzyme is also active against double-stranded DNA and RNA and all sequences will be ultimately cleaved.

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Essential Laboratory Skills Guide

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Characteristics

The enzyme has a molecular weight of 16.9kDa.

The pH optimum is reported as 9.2. The enzyme activity is strictly dependent on Ca²⁺ and the pH optimum varies according to Ca2+ concentration.^[1] The enzyme is therefore easily inacitvated by EDTA.

Source

This enzyme is the extracellular nuclease of Staphylococcus aureus. Two strains, V8 and Foggi, yield almost identical enzymes.^[2] A common source is E.coli cells carrying a cloned nuc gene encoding Staphylococcus aureus extracellular nuclease (micrococcal nuclease).

Applications

• Hydrolysis of nucleic acids in crude cell-free extracts.
• Sequencing of RNA.
• Preparation of rabbit reticulocytes lysates
• Studies of chromatin structure.
• Remove nucleic acids from protein preparation allowing for folding and structure-function studies.

References

1. ^ Heins JN, Suriano JR, Taniuchi H, Anfinsen CB (1967). "Characterization of a nuclease produced by Staphylococcus aureus". J. Biol. Chem. 242 (5): 1016-20. PMID 6020427.
2. ^ Cusumano CL, Taniuchi H, Anfinsen CB (1968). "Staphylococcal nuclease (Foggi strain). I. Order of cyanogen bromide fragments and a "fourth" histidine residue". J. Biol. Chem. 243 (18): 4769-77. PMID 5687719.

• http://www.fermentas.com/catalog/modifyingenzymes/nucleasemicrococcal.htm

• http://www.worthington-biochem.com/NFCP/default.html

• http://www.fermentas.com/pdf/msds/en0181_eu.pdf#search=%22micrococcal%20nuclease%22 - A material and safety data sheet for the product