A nuclease is an enzyme which can cleave nucleic acids at phosphodiester bonds.
Structure of nucleases
Like all enzymes, nucleases are proteins which have an active site for the enzyme reaction and a target molecule recognition site which gives the reaction its specificity.
Function of nucleases
Nucleases break phosphodiester bonds between nucleotides. There are two types of these enzymes:
- Endonucleases, which create cuts within the DNA or RNA chains themselves and as such create two separate strands;
- and exonucleases which detach nucleotides at the ends of the DNA or RNA chains.
There are also the ribonucleases which only act on ribonucleic acids (RNA), together with the deoxyribonucleases which cleave deoxyribonucleic acid (DNA).
DNA can be cleaved by deoxyribonucleases. © Caroline Davis, Flickr, CC