Micrococcal Nuclease (S7 Nuclease or MNase) 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.

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. 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. 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

• 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

External links