Question

You have discovered a mutant DNA polymerase that decreases the binding affinity between the polymerase active site and the nucleotide triphosphate (KM is increased). The exonuclease activity of the polymerase is unaffected. Which of the following properties do you predict the mutant polymerase will have?

(A) It will polymerize in both the 5' to 3' and 3' to 5' direction
(B) It will polymerize more slowly than the normal polymerase
(C) It will be more likely to generate mismatched base pairs
(D) All of the above

Answer 1

The mutant polymerase with decreased binding affinity will polymerize in both directions, polymerize more slowly, and generate mismatched base pairs.

Step-by-step explanation:

The mutant polymerase that decreases the binding affinity between the polymerase active site and the nucleotide triphosphate would have the following properties:

• (A) It will polymerize in both the 5' to 3' and 3' to 5' direction
• (B) It will polymerize more slowly than the normal polymerase
• (C) It will be more likely to generate mismatched base pairs

Therefore, the correct answer is (D) All of the above.