Restriction Enzyme Action of EcoRI
The EcoRI restriction enzyme--the first restriction enzyme isolated from E. Coli bacteria--is able to recognize the base sequence 5' GAATTC 3'. Restriction enzymes cut each strand of DNA between the G and the A in this sequence. This leaves "sticky ends" or single stranded overhangs of DNA. Each single stranded overhang has the sequence 5" AATT 3'. These overhanging ends will bond to a fragment of DNA which has the complementary sequence of bases. See text of Background Paper for additional details.
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