38.2.91 - DNA

In the reaction catalyzed by DNA ligase

1. an AMP group is covalently attached to a 5'-phosphate group at a nick in double-stranded DNA.
2. an AMP group is covalently attached to a 3'-hydroxyl group at a nick in double-stranded DNA.
3. the 3'-hydroxyl group at the nick displaces AMP from the DNA.
4. a water molecule cleaves the AMP group from the DNA.

• a. if 1, 2, and 3 are correct
• b. if 1 and 3 are correct
• c. if 2 and 4 are correct
• d. if only 4 is correct
• e. if all are correct