Micrococcal nuclease

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Micrococcal nuclease
Staph nuclease 3h6m ribbon.jpg
Ribbon schematic of micrococcal nuclease 3D structure, with Ca2+ and TdtP inhibitor
Identifiers
EC no. 3.1.31.1
CAS no. 9013-53-0
Databases
IntEnz IntEnz view
BRENDA BRENDA entry
ExPASy NiceZyme view
KEGG KEGG entry
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum
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PMC articles
PubMed articles
NCBI proteins
Thermonuclease
Identifiers
Organism Staphylococcus aureus
Symbolnuc
UniProt P00644
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Structures Swiss-model
Domains InterPro
Staphylococcal nuclease
Identifiers
Symbol?
Pfam PF00565
InterPro IPR016071
PROSITE PDOC00865
CATH 1tt2
SCOP2 1tt2 / SCOPe / SUPFAM
Available protein structures:
Pfam   structures / ECOD  
PDB RCSB PDB; PDBe; PDBj
PDBsum structure summary

Micrococcal nuclease (EC 3.1.31.1, S7 Nuclease , MNase, spleen endonuclease, thermonuclease, nuclease T, micrococcal endonuclease, nuclease T', staphylococcal nuclease, spleen phosphodiesterase, Staphylococcus aureus nuclease, Staphylococcus aureus nuclease B, ribonucleate (deoxynucleate) 3'-nucleotidohydrolase) 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. [1] The enzyme is also active against double-stranded DNA and RNA and all sequences will be ultimately cleaved.

Contents

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. [2] The enzyme is therefore easily inactivated by EGTA.

Sources

This enzyme is the extracellular nuclease of Staphylococcus aureus . Two strains, V8 and Foggi, yield almost identical enzymes. [3] A common source is E.coli cells carrying a cloned nuc gene encoding Staphylococcus aureus extracellular nuclease (micrococcal nuclease).

Structure

The 3-dimensional structure of micrococcal nuclease (then called Staphyloccal nuclease) was solved very early in the history of protein crystallography, in 1969. [4] Higher-resolution, more recent crystal structures are available for the apo form [5] and for the thymidine-diphosphate-inhibited form. [6] [7] As seen in the ribbon diagram above, the nuclease molecule has 3 long alpha helices and a 5-stranded, barrel-shaped beta sheet, in an arrangement known as the OB-fold (for oligonucleotide-binding fold) as classified in the SCOP database.

Applications

See also

References

  1. Colin Dingwall, George P. Lomonossoff, Ronald A. Laskey, High sequence specificity of micrococcal nuclease, Nucleic Acids Research, Volume 9, Issue 12, 25 June 1981, Pages 2659–2674, https://doi.org/10.1093/nar/9.12.2659
  2. Heins JN, Suriano JR, Taniuchi H, Anfinsen CB (1967). "Characterization of a nuclease produced by Staphylococcus aureus". J. Biol. Chem. 242 (5): 1016–20. doi: 10.1016/S0021-9258(18)96225-3 . PMID   6020427.
  3. 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. doi: 10.1016/S0021-9258(18)93185-6 . PMID   5687719.
  4. Arnone A, Bier J, et al. (1971). "A High Resolution Structure of an Inhibitor Complex of the Extracellular Nuclease of Staphylococcus aureus: I. Experimental Procedures and Chain Tracing". J. Biol. Chem. 246 (7): 2303–2316. doi: 10.1016/S0021-9258(19)77221-4 . PMID   5555571.
  5. Truckses, D.M., Prehoda, K.E., Miller, S.C., Markley, J.L. and Somoza, J.R. (1996), Coupling between trans/cis proline isomerization and protein stability in staphylococcal nuclease. Protein Science, 5: 1907-1916. https://doi.org/10.1002/pro.5560050917 PDB: https://www.rcsb.org/structure/1SNO
  6. Khangulov, V.S., Schlessman, J.L., Heroux, A., Garcia-Moreno, E.B. Crystal structure of Staphylococcal nuclease variant Delta+PHS V104E at cryogenic temperature PDB: https://www.rcsb.org/structure/3H6M
  7. Loll, P.J. and Lattman, E.E. (1989), The crystal structure of the ternary complex of staphylococcal nuclease, Ca2+ and the inhibitor pdTp, refined at 1.65 Å. Proteins, 5: 183-201. https://doi.org/10.1002/prot.340050302 PDB: https://www.rcsb.org/structure/1SNC