why E. coli's own DNA is not cut by the restriction endonuclease EcoRI?

Answer 1

EcoRI is a restriction enzyme produced by E.coli to cut up pieces of virus DNA. They are the bacterial version of an immune system. The way the restirction enzymes avoid cutting self DNA is by a specific methylation pattern of the genome.

DNA from outside the cell ie virus DNA wont have this pattern of methylation, and os the restriction enzymes can bind and cut the DNA.

Answer 2

I think some E.coli are affected by it, but let's say they don't. EcoRI was derived from E.coli. They use it as there form of anti-biotic to ride themselves of their competition. Simply, it doesn't cut itself because it doesn't have the recognition site for ECORI- since it is designed to harm other bacteria. The name of the RE is misleading sometimes

Answer 3

the way that restriction enzymes work they cut out introns which is junk DNA prokaryotes do not have introns therefore restriction enzymes will not cut out the excess DNA that is not their

Answer 4

Methalation at the site. Common self protection.