PROSITE documentation PDOC00821
DNA/RNA non-specific endonucleases active site


A family of bacterial and eukaryotic endonucleases (EC 3.1.30.-) share the following characteristics: they act on both DNA and RNA, cleave double-stranded and single-standed nucleic acids and require a divalent ion such as magnesium for their activity. The enzymes that belongs to this family are:

  • Extracellular nuclease from Serratia marcescens.
  • Extracellular nuclease nucA from the cyanobacteria Anabaena PCC 7120.
  • DNA-entry nuclease from Streptococcus pneumoniae.
  • Mammalian mitochondrial endonuclease G (endo G).
  • Yeast mitochondrial endonuclease NUC1.
  • Nuclease C1 from the fungi Cunninghamella echinulata.

An histidine has been shown [1] to be essential for the activity of the Serratia marcescens nuclease. This residue is located in a conserved region which can be used as a signature pattern and which also contains an aspartic acid residue that could be implicated in the binding of the divalent ion.

Expert(s) to contact by email:

Friedhoff P.

Last update:

July 1999 / Pattern and text revised.


Technical section

PROSITE method (with tools and information) covered by this documentation:

NUCLEASE_NON_SPEC, PS01070; DNA/RNA non-specific endonucleases active site  (PATTERN)


1AuthorsFriedhoof P. Gimadutdinow O. Pingoud A.
TitleIdentification of catalytically relevant amino acids of the extracellular Serratia marcescens endonuclease by alignment-guided mutagenesis.
SourceNucleic Acids Res. 22:3280-3287(1994).
PubMed ID8078761

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