Endonuclease enzyme

An **endonuclease enzyme** is a type of nuclease that cleaves phosphodiester bonds within a nucleic acid strand, breaking the DNA or RNA at internal sites rather than from the ends[1][2][3][6]. These enzymes play central roles in biological processes such as DNA repair, DNA replication, recombination, and restriction-modification systems, as well as the defense against foreign genetic material in prokaryotes[2][6][8]. Important subtypes include **restriction endonucleases** (commonly called restriction enzymes), which recognize and cut DNA at specific sequences and are widely used in molecular cloning, and repair endonucleases involved in removing damaged or mismatched DNA[1][3][8][9]. Endonucleases can cut double- or single-stranded DNA and even RNA, and are classified by their sequence specificity and mechanism of action. Their key function in DNA repair is essential for maintaining genetic stability and preventing diseases such as cancer[2][3][6].

Other names

Endonuclease

Cleavage of phosphodiester bonds within DNA or RNA; Facilitation of DNA repair by generating DNA breaks at or near damaged or mismatched regions; Generation of DNA fragments for recombinant DNA or molecular cloning