Question

Observe the given sequence of nitrogenous bases on a DNA fragment and answer the following questions:

5'

C

A

G

A

A

T

T

C

T

T

A

3'

3'

G

T

C

T

T

A

A

G

A

A

T

5'

1. Name the restriction enzyme which can recognise the DNA sequence.
2. Write the sequence after restriction enzyme cut the palindrome.
3. Why are the ends generated after digestion called as ‘Sticky Ends’?

Answer 1

1. EcoRI is the restriction enzyme that can identify the provided palindromic sequence (5'-GAATTC-3').
2. The DNA sequence between G and A is cut by EcoRI, producing the following sticky-ended fragments:
   5'-CAGAATTCTTA-3' becomes 5'CAG3' + 5'AATTCTTA3'
   3'-GTCTTAAGAAT-5' becomes 3'GTCTTAA5' + 3'GAAT5'
3. Due to their single-stranded overhangs, the ends produced after digestion are known as “sticky ends.” These overhangs can ‘stick’ to other DNA fragments with matching ends because they can readily create base pairs with complementary sequences. Because it makes it possible to link various DNA segments, this characteristic is essential for recombinant DNA technology.