I don't get the point of restriction endonucleases cleaving the DNA strands. What's the point of ligase gluing everything back together after the strands are cut?

Question

anonymous · Answer

this thing happen to remove impurities

anonymous · Answer

restriction endonucleases were first invented in 1968 by some british guy. what's up with that? :D

seriously though. endonucleases cut out DNA that's not your own. at least in bacteria, they do that as a protection against viral DNA. and since the DNA is a ring, you will want a ring when the process is done. so the endonuclease cuts out the malignant DNA, and ligase smelts together the organism's DNA afterwards.

anonymous · Answer

Restriction endonucleases were not invented they were discovered some bacteria have them as a defense mechanism against viruses.

anonymous · Answer

yaay, caught my joke!