Restriction Enzyme

Name:
Restriction Enzyme
Detailed information:
(restriction endonucleases). A class of enzymes generally isolated from bacteria, which are able to recognize and cut specific sequences (restriction sites) in DNA. Every copy of a plasmid is identical in sequence, so if an enzyme cuts a particular circular plasmid at three sites producing three “restriction fragments”, then a million copies of that plasmid will produce those same restriction fragments a million times over. There are more than six hundred known restriction enzymes. Bacteria produce restriction enzymes for protection against invasion by foreign DNA such as phages. The bacteria's own DNA is modified in such a way as to prevent it from being clipped.