Question

Which of the following is a correct statement regarding sticky end fragments produced by restriction enzymes?

• A. They are produced by all restriction endonucleases
• B. In recombinant DNA technology blunt ends are more preferred as they have overhangs
• C. The stickiness of the end facilitates the action of DNA polymerase
• D. They are named sticky ends because they form hydrogen bonds with their complementary cut counterparts

Answer 1

The correct option is D They are named sticky ends because they form hydrogen bonds with their complementary cut counterparts

Restriction endonucleases recognize specific nucleotide sequences in a DNA molecule, often a palindrome, known as restriction site, and cleave the DNA at a specific nucleotide within the restriction site. Upon action, restriction enzymes produce fragments with two types of ends namely blunt end and sticky end.
Blunt ends

• No overhangs are produced
• The cleavage site lies exactly on the axis of symmetry

Sticky ends

• Overhangs are produced either at 5’ or 3’ end
• The cleavage site is away from the axis of symmetry
• They are named sticky ends because they form hydrogen bonds with their complementary cut counterparts

In recombinant DNA technology sticky ends are more preferred as they have overhangs which will help in hydrogen bonds formation with their complementary cut counterparts.