Question

How is phosphatase related to the ligation reactions?

(a) Phosphate group is not required for the ligation reaction to take place, thus phosphatase is helpful

(b) It is helpful in ceasing the unwanted ligation

(c) Phosphatases are not at all related to ligation reactions

(d) They act as a catalyst in case of the ligation reaction

This question was addressed to me during an online exam.

This intriguing question comes from Restriction Endonuclease & Phosphatases topic in section Basics of Genetic Engineering of Genetic Engineering

Answer 1

Correct answer is (b) It is helpful in ceasing the unwanted ligation

The explanation is: Phosphatses are used to stop unwanted ligation. It is so because if phosphatases are present, phosphate would be removed from the ends and it would further block the ligation. It is so because the phosphate group is necessary for ligation to take place.