Why restriction enzyme cannot cut its own DNA?
Restriction enzymes are produced by bacteria to help destroy foreign, invading DNA, such as the DNA of bacteriophage (a virus that infects bacterial cells). Every restriction enzyme comes with a methylase enzyme, or more specifically, a DNA methyltransferase. The methylase enzyme methylates (adds a methyl group) to the restriction endonuclease site on the cell’s own DNA, which protects the sites from the restriction enzyme so that it does not degrade its own DNA.
