noun, plural: nucleases
Different enzymes are used for manipulating DNA. One of them is a group of enzymes that promotes the hydrolysis of nucleic acids, such as DNA; others are DNA polymerases, kinases, alkaline phosphatases, and topoisomerases.
There are two major types of nucleases: (1) exonucleases and (2) endonucleases. Exonucleases are capable of removing nucleotides one at a time from a DNA molecule whereas endonucleases work by cleaving the phosphodiester bonds within DNA molecule.1 Examples of nucleases are Bal 31, which is a double-stranded exonuclease commonly used for producing deletion sets, exonuclease I and exonuclease III for 3'-5' exonuclease activity, Dnase I, which is an endonuclease used for splitting single-stranded and double-stranded DNA molecules, and nuclease S1 capable of degrading both single-stranded DNA and RNA molecules. (There are however certain nucleases that act as both an endonuclease and an exonuclease.)