Question

Palimdromic DNA sequence for EcoRI is

• A. a. 5`- GATTA-3`
• B. b.5`-GATTAG-3`
• C. c.3`- CTTAAG-5`
• D. D 3`-ATTGAG-5`

Answer 1

The correct option is C c.3`- CTTAAG-5`

A palindromic sequence is a sequence made up of nucleic acids within double helix of DNA that is the same when reading from 5' to 3' on one strand and 5' to 3' on the other, complementary, strand. It is also known as a palindrome or an inverted-reverse sequence. EcoRI creates 4 nucleotide sticky ends with 5' end overhangs of AATT. The nucleic acid recognition sequence where the enzyme cuts are 5'- G/AATTC -3', which has a palindromic, complementary sequence of 3'- CTTAA/G-5'. The / in the sequence indicates which phosphodiester bond the enzyme will break in the DNA molecule.

So, the correct answer is '3'-CTTAAG-5'.