Question

Given below is the restriction site of a restriction endonuclease Pst I and the cleavage sites on a DNA molecule. \[ 5' C - T - G - C - A \, \downarrow \, G 3'
3' G - A - C - G - T - C 5' \] Choose the option that gives the correct resultant fragments.

• A. 5' C - T - G - C - A \, C - A - G 3'
  3' G - A - C - G - T \, C 5'
• B. 5' C - T - G - C - A \, G - C - A - G 3'
  3' G - A - C - G \, T - C 5'
• C. 5' C - T - G - C - A \, A - G 3'
  3' G - A - C - G \, T - C 5'
• D. 5' C - T - G - C - A \, G 3'
  3' G - A - C - G - T - C 5'

Hint:

Restriction enzymes like Pst I create sticky ends by cutting between specific bases, allowing for easier ligation of fragments.

Answer 1

The Correct Option is A

Step 1: Understanding the restriction site.
Pst I is a restriction enzyme that recognizes and cuts DNA at the sequence 5' C - T - G - C - A 3', with a sticky end created at the cleavage site.
Step 2: Analyzing the cleavage.
The enzyme cuts between the G and C, resulting in two fragments: 1. 5' C - T - G - C - A \, C - A - G 3' 2. 3' G - A - C - G - T \, C 5'
Step 3: Conclusion.
The correct resultant fragments are option (A) 5' C - T - G - C - A \, C - A - G 3' and 3' G - A - C - G - T \, C 5'.
Final Answer: (A) 5' C - T - G - C - A \, C - A - G 3'
3' G - A - C - G - T \, C 5'.