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Date of Award


Document Type

Restricted Thesis: Campus only access

Degree Name

Bachelor of Science



First Advisor

Dr. Jeff Elhai


Many bacteria have evolved a defense mechanism against foreign DNA: restriction enzymes (Bickle and Kruger, 1993). These proteins patrol the cell and degrade intruding DNA, thus protecting the cell from outside DNA. Restriction enzymes recognize specific sequences in DNA (-AATCG- for example) called restriction sites. Obviously, the bacteria must protect their own DNA from their restriction enzymes, and a common defense would be to attach a molecule (such as a methyl group, -CH3) to the DNA so the enzyme cannot fit around its restriction site. What if an invading strand of DNA has this same protection?