Question

Which of the following statement about DNA polymerase III is NOT correct?

• A. Possesses \(5^{\prime}\rightarrow3^{\prime}\) polymerase activity
• B. Have a polymerization rate of 250-1000 nts/sec
• C. Possesses \(3^{\prime}\rightarrow5^{\prime}\) exonuclease activity
• D. Possesses \(5^{\prime}\rightarrow3^{\prime}\) exonuclease activity

Hint:

DNA Pol III: \(5^{\prime}\rightarrow3^{\prime}\) polymerase and \(3^{\prime}\rightarrow5^{\prime}\) exonuclease.
\(5^{\prime}\rightarrow3^{\prime}\) exonuclease: DNA Pol I.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
DNA polymerase III is the main replicative enzyme.
It has specific enzymatic activities.

Step 2: Key Formula or Approach:
No specific formula.
Need to know the properties of DNA polymerase III.

Step 3: Detailed Explanation:
DNA polymerase III:
- Possesses \(5^{\prime}\rightarrow3^{\prime}\) polymerase activity (A is correct).
- Has a polymerization rate of 250-1000 nt/sec (B is correct).
- Possesses \(3^{\prime}\rightarrow5^{\prime}\) exonuclease activity (C is correct).
- Does NOT possess \(5^{\prime}\rightarrow3^{\prime}\) exonuclease activity (D is incorrect).
This activity is present in DNA polymerase I.
Thus, the incorrect statement is that it possesses \(5^{\prime}\rightarrow3^{\prime}\) exonuclease activity.

Step 4: Final Answer:
The incorrect statement is that DNA polymerase III possesses \(5^{\prime}\rightarrow3^{\prime}\) exonuclease activity.
Hence, the correct option is (D).