Homework SourseAs a result of DNA helicase activity topoisomerases are also
As a result of DNA helicase activity, topoisomerases are also required during replication. Explain how topoisomerases help DNA helicases function more efficiently.
| A. Topoisomerases prevent formation of negative supercoils. |
| B. Topoisomerases prevent formation of positive supercoils. |
| C. Topoisomerases cause formation of positive supercoils. |
| D. Topoisomerases cause formation of negative supercoils. |
Solution
A. Topoisomerase prevent formation of positive supercoil.
During DNA replication, helicase unwinds the DNA and forms positive supercoil infront of helicase. If this supercoil is not processed or cleared - DNA replication totally inhibited or stoped. So, to remove this positive supercoil Topoisomerase II or gyrase makes a double strand break and relax the DNA strand for further replication.
