Question

Choose the correct sequence for how a type I topoisomerase relaxes DNA.
A. DNA release
B. Cleavage and opening of gate
C. Rejoining of cleaved strand
D. Strand passage

• A. A, B, C, D
• B. B, D, C, A
• C. A, D, B, C
• D. C, A, D, B

Hint:

Type I topoisomerase cuts ONE strand (Type I = 1 strand), whereas Type II topoisomerase cuts TWO strands. The general mechanism is always: Cut (Cleavage) $\rightarrow$ Pass (Strand passage) $\rightarrow$ Seal (Rejoining) $\rightarrow$ Let go (Release).

Answer 1

The Correct Option is B