AP BIOLOGY

Detailed explanation-1: -EcoRI was discovered in Herbert Boyer’s lab. It is a type II restriction enzyme, which cuts specifically at the restriction site having 5’-GAATTC-3’ sequence. It cuts the DNA at a specific site forming sticky ends. Restriction site of EcoRI is a palindrome and it cuts DNA after G forming sticky ends with AATT.

Detailed explanation-2: -GAATTC is recognition site of restriction endonuclease EcoR I. EcoR I is the restriction enzyme, derived from Escherichia coli, strain R and is the first to be isolated. EcoR I recognizes and cuts at the specific restriction site 5’-GAATTC-3’ and produces sticky ends.

Detailed explanation-3: -It is a type II restriction enzyme that cuts only at the restriction site with the 5’-GAATTC-3’ sequence. It chops the DNA at a specified location, resulting in sticky ends. EcoRI has a palindrome recognition site that cuts DNA following G, creating sticky ends with AATT.

Detailed explanation-4: -Note, after a reaction with the EcoRI enzyme, that the DNA of species A is cleaved into three fragments, corresponding to two EcoRI restriction sites, whereas that of species B is cleaved into four fragments, corresponding to three EcoRI restriction sites.

Detailed explanation-5: -EcoRI recognizes the sequence GAATTC, and cuts both DNA strands between the G and the A nucleotides. Protruding from the cut ends will be single-stranded DNA “tails” having the sequences AATT.