DNase I

DNase I is an endonuclease that can randomly degrade single stranded or double stranded DNA with equal efficiency to release di-, tri- and oligonucleotide products with 5´-phosphorylated and 3´-hydroxylated ends. DNase I acts on single- and double-stranded DNA, chromatin and RNA:DNA hybrids. The bioactivity of DNase I is highly dependent on Ca²⁺, Mg²⁺ or Mn²⁺. In the presence of Mg²⁺, DNase I cleaves each strand of dsDNA independently in a statistically random fashion. In the presence of Mn²⁺, the enzyme cleaves both DNA strands at approximately the same site, producing DNA fragments with blunt-ends or with overhang termini of only one or two nucleotides.