Mechanism of ligation for both T4 DNA ligase and E. coli DNA ligase makes use of Adenosine Monophosphate (AMP). Which of the steps is involved in the ligation mechanism?

Correct Answer: AMP is added to the 5’ phosphate of one of the DNA molecule
AMP is added to the 5’ phosphate of one of the DNA molecule. It leads to the liberation of pyrophosphate from ATP and nicotanamide mononucleotide from NAD. It is further displaced by nucleophilic attack by 3’ hydroxyl of the other DNA molecule.