A nicking enzyme (or nicking endonuclease) is an enzyme that cuts only one strand of a double-stranded DNA or RNA molecule[1] at a specific recognition nucleotide sequence known as the restriction site.
Such enzymes hydrolyze (cut) only one strand of the DNA duplex, to produce DNA molecules that are “nicked”, rather than cleaved.
[2][3] They can be used for strand-displacement amplification,[4] Nicking Enzyme Amplification Reaction, exonucleolytic degradation, the creation of small gaps,[5] or nick translation.
[6] The latter process has been successfully used to incorporate both radioactively labelled nucleotides and fluorescent nucleotides allowing specific regions on a double stranded DNA to be studied.
[6][7] Over 200 nicking enzymes have been studied, and 13 of these are available commercially[8] and are routinely used for research and in commercial products.