PROSITE documentation PDOC00711
Deoxyribonuclease I signatures


Deoxyribonuclease I (DNase I) (EC [1] is a vertebrate enzyme which catalyzes the endonucleolytic cleavage of double-stranded DNA to 5'-phosphodinucleotide and 5'-phosphooligonucleotide end-products. DNase I is an enzyme involved in DNA degradation; it is normally secreted outside of the cell but seems to be able to gain access to the nucleus where it is involved in cell death by apoptosis [2].

As shown in the following schematic representation, DNase I is a glycoprotein of about 260 residues with two conserved disulfide bonds.

                              +-+               +--------+
                              | |               |        |
                                    ****     ****
'C': conserved cysteine involved in a disulfide bond.
'#': active site residue.
'*': position of the patterns.

DNase I has a pH-optimum around 7.5 and requires calcium and magnesium for full activity. It causes single strand nicks in duplex DNA. A proton acceptor-donor chain composed of an histidine and a glutamic acid produce a nucleophilic hydroxyl ion from water, which cleaves the 3'-P-O bond [3]. DNase I is inhibited by actin with which it forms a stoechiometric 1:1 complex [4].

The sequence of DNase I is evolutionary related to that of:

  • Human muscle-specific DNase-like protein (gene DNASE1L1 or DNL1L) [5].
  • Human protein DHP1 (gene DNASE1L2) [6].
  • Human protein DHP2 (gene DNASE1L3) [6].

The first disulfide bond of DNase I is not conserved in the above proteins.

Last update:

April 2006 / Pattern revised.


Technical section

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

DNASE_I_1, PS00919; Deoxyribonuclease I signature 1  (PATTERN)

DNASE_I_2, PS00918; Deoxyribonuclease I signature 2  (PATTERN)


1AuthorsSuck D. Oefner C.
TitleStructure of DNase I at 2.0 A resolution suggests a mechanism for binding to and cutting DNA.
SourceNature 321:620-625(1986).
PubMed ID3713845

2AuthorsPeitsch M.C. Polzar B. Stephan H. Crompton T. MacDonald H.R. Mannherz H.G. Tschopp J.
TitleCharacterization of the endogenous deoxyribonuclease involved in nuclear DNA degradation during apoptosis (programmed cell death).
SourceEMBO J. 12:371-377(1993).
PubMed ID8428592

3AuthorsSuck D. Lahm A. Oefner C.
TitleStructure refined to 2A of a nicked DNA octanucleotide complex with DNase I.
SourceNature 332:464-468(1988).
PubMed ID3352748

4AuthorsKabsch W. Mannherz H.G. Suck D. Pai E.F. Holmes K.C.
TitleAtomic structure of the actin:DNase I complex.
SourceNature 347:37-44(1990).
PubMed ID2395459

5AuthorsParrish J.E. Ciccodicola A. Wehhert M. Cox G.F. Chen E. Nelson D.L.
TitleA muscle-specific DNase I-like gene in human Xq28.
SourceHum. Mol. Genet. 4:1557-1564(1995).
PubMed ID8541839

6AuthorsRodriguez A.M. Rodin D. Nomura H. Morton C.C. Weremowicz S. Schneider M.C.
TitleIdentification, localization, and expression of two novel human genes similar to deoxyribonuclease I.
SourceGenomics 42:507-513(1997).
PubMed ID9205125

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