Restriction Modification System

The Restriction Modification System is a bacterial defense mechanism that protects against invading genetic material like viruses. It involves two parts: a modification enzyme that tags the bacterium's own DNA with specific markers to identify it as "self," and a restriction enzyme that recognizes and cuts foreign DNA lacking these markers. If harmful DNA, such as a virus, enters the cell, the restriction enzyme breaks it apart, preventing infection. This system helps bacteria distinguish between their own DNA and potentially harmful foreign DNA, maintaining their genetic integrity.