How do bacterial cells proect their own DNA from restriction?

Question

typing mistake...*protect

Answer 1

They do not have the sequence of DNA that the restriction enzyme recognizes and cuts

Answer 2

A restriction enzyme (or restriction endonuclease) is an enzyme that cuts double-stranded DNA. The enzyme makes two incisions, one through each of the sugar-phosphate backbones (i.e., each strand) of the double helix without damaging the nitrogenous bases. The term restriction comes from the fact that these enzymes were discovered in E. coli strains that appeared to be restricting the infection by certain bacteriophages. Restriction enzymes therefore are believed to be a mechanism evolved by bacteria to resist viral attack and to help in the removal of viral sequences.

The restriction enzyme does not cut the host DNA.

Answer 3

methylation.

each bacteria has a collection of restriction enzymes that it uses... For each of these restriction enzyme sequences, it has complementary methylation enzymes that will attach a CH3 group to that DNA sequence, which prevents the restriction enzyme from recognizing the sequence and destroying it.