Systems consisting of two enzymes, a modification methylase and a restriction endonuclease. They are closely related in their specificity and protect the DNA of a given bacterial species. The methylase adds methyl groups to adenine or cytosine residues in the same target sequence that constitutes the restriction enzyme binding site. The methylation renders the target site resistant to restriction, thereby protecting DNA against cleavage.

Synonyms: DNA Restriction Modification Enzymes, System, Restriction-Modification, Systems, Restriction-Modification, Systems, Restriction Modification, System, Restriction Modification, DNA Restriction-Modification Enzymes, Restriction Modification System, Restriction-Modification Systems, Restriction-Modification Enzymes, DNA, Enzyme, DNA Restriction-Modification, DNA Restriction Modification Enzyme, 0, Restriction-Modification Enzyme, DNA, Restriction Modification Systems, Modification System, Restriction, Enzymes, DNA Restriction-Modification, DNA Restriction-Modification Enzyme, Modification Systems, Restriction, Restriction-Modification System