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A Fluorescence-based Exonuclease Assay to Characterize DmWRNexo, Orthologue of Human Progeroid WRN Exonuclease, and Its Application to Other Nucleases
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[Endonuclease from Proteus mirabilis]

Z Z Salikhova1, R B Sokolova, A Z Ponomareva

  • 1Kazan State University, Kazan, 420008 Russia.

Prikladnaia Biokhimiia I Mikrobiologiia
|March 10, 2001
PubMed

Insights

Proteus mirabilis secretes a potent endonuclease, Pm endonuclease, with both DNase and RNase activity. This enzyme efficiently cleaves DNA and requires specific conditions for optimal function.

Area of Science:

  • Microbiology
  • Enzymology

Background:

  • Proteus mirabilis possesses nucleases with DNase and RNase activities.
  • These nucleases are found in the culture liquid and periplasm.

Purpose of the Study:

  • To isolate and purify the nuclease from Proteus mirabilis.
  • To characterize the enzymatic properties of the purified nuclease, designated Pm endonuclease.

Main Methods:

  • Isolation of the enzyme from the periplasm of Proteus mirabilis.
  • Purification to a functionally homogeneous state.
  • Enzymatic assays to determine substrate specificity and optimal conditions.

Main Results:

  • The purified enzyme, Pm endonuclease, exhibits potent DNase and RNase activities.
  • It cleaves both denatured and native DNAs via an endonuclease mechanism.
  • Optimal activity occurs at pH 10.4-10.6, is temperature-dependent, requires bivalent metal ions, and is inhibited by citrate and EDTA.

Conclusions:

  • Proteus mirabilis produces a versatile endonuclease with significant DNase and RNase capabilities.
  • Pm endonuclease is a novel enzyme with specific biochemical requirements, offering potential for biotechnological applications.

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