Endonuclease and DNA, molecular model 插畫檔

Endonuclease and DNA. Molecular model of an endonuclease restriction enzyme (yellow) bound to a molecule of DNA (deoxyribonucleic acid). Restriction enzymes, also known as restriction endonucleases, recognise specific nucleotide sequences and cut the DNA at these sites. They are found in bacteria and archaea and are though to have evolved as a defence against viral infection.