Thermolabile duplex-specific nuclease

Biotechnol Lett. 2009 Feb;31(2):251-7. doi: 10.1007/s10529-008-9850-y. Epub 2008 Sep 23.


Using random mutagenesis of the gene encoding duplex-specific nuclease from the king crab we found a new mutant that retained all properties of the wild-type protein, but exhibited a much lower thermal stability. This enzyme, denoted thermolabile duplex-specific nuclease (DSN-TL), exhibits high processivity and selective cleavage of dsDNA. The inactivation temperature for DSN-TL is 15-20 degrees C lower than that of the widely used DNase I and shrimp nuclease, and its catalytic activity is more than 10 times higher. Moreover, DSN-TL is resistant to proteinase K treatment. These properties make DSN-TL very useful for removing genomic DNA from RNA samples intended for quantitative RT-PCR.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites
  • Brachyura / enzymology*
  • Brachyura / genetics
  • Catalysis
  • DNA / chemistry*
  • DNA / genetics*
  • Deoxyribonucleases / chemistry*
  • Deoxyribonucleases / genetics*
  • Enzyme Activation
  • Enzyme Stability
  • Mutagenesis, Site-Directed
  • Protein Binding
  • Protein Engineering / methods
  • Structure-Activity Relationship
  • Temperature


  • DNA
  • Deoxyribonucleases