Which of the Following is NOT a Requirement of E

Question

Which of the following is NOT a requirement of E. coli DNA ligase?
A) A nick in the DNA strand must have a 3' OH group.
B) A nick in the DNA strand must have a 5' phosphate group.
C) The nucleotides being linked must be adjacent in the duplex structure.
D) The nucleotides being linked must be properly based-paired.
E) ATP

Accepted Answer

E. coli DNA ligase uses NAD+ or ATP as a cofactor, so ATP is actually a requirement of the enzyme. Therefore, the answer is E, which is the option that does not correctly describe a requirement of E. coli DNA ligase. The actual requirements are that the nick in the DNA strand must have a 3' OH group, a nick in the DNA strand must have a 5' phosphate group, the nucleotides being linked must be adjacent in the duplex structure, and the nucleotides being linked must be properly based-paired.