22-01-2016 16:47 via phys.org

Where wood is chopped, splinters must fall

Bacteria and other prokaryotes have been around for billions of years because they managed to develop successful evolutionary strategies for survival. For instance, they possess defense mechanisms that allow them to discriminate between self and non-self DNA in the event of a virus infection. These defense mechanisms are called restriction-modification systems and are based on the balance between the two enzymes M (methyltransferase) and R (restriction endonuclease). M tags endogenous DNA as sel
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