EcoRI is a commonly used restriction enzyme derived from the bacterium Escherichia coli. It recognizes and cuts DNA at a specific DNA sequence known as the EcoRI recognition site. The EcoRI recognition site is a palindromic sequence, meaning it reads the same on both DNA strands when oriented in the 5' to 3' direction. The EcoRI recognition site is: 5'-GAATTC-3' 3'-CTTAAG-5' EcoRI cuts the DNA at this site between the G and A nucleotides, specifically within the two central base pairs. This results in the generation of two DNA fragments with "sticky ends" that have single-stranded overhangs. The overhangs of the DNA fragments can base pair with complementary overhangs from other DNA fragments cut with the same enzyme, allowing for the fragments to be easily joined together through DNA ligation. The specific cutting position of EcoRI within the recognition site is depicted as follows: 5'-G AATTC-3' | | | ˅ 3'-CTTAA G-5' The location of the cut site creates cohesive ends, with a 5' overhang (3'-AATT) on one fragment and a complementary 3' overhang (5'-TTAA) on the other fragment. These cohesive or sticky ends facilitate the subsequent ligation of DNA fragments, enabling the construction of recombinant DNA molecules.