(Solved): Problem 3 DNA Topology 3) In Eukaryotic Cells, DNA Wraps Around A Complex Of Histone Proteins Into N...

Problem 3 DNA Topology 3) In eukaryotic cells, DNA wraps around a complex of histone proteins into nucleosomes, allowing DNA to be packaged into the nucleus. You want to study nucleosomes and linking number. You have a piece of circular DNA that is 2400 bps in length. a) Assume your DNA has 10 bps/turn, with an initial writhe = 0. What is the twist and linking number of your DNA? b) You now add 7 histone complexes, which your DNA wraps around to create a total of 7 nucleosomes. This results in a writhe = 12. What will be the new twist and linking number of your DNA? c) Based on this writhe, how many times does DNA wind around one histone complex? d) To release the supercoils, what enzyme can you add to the system? How many cycles does the enzyme need to work to release all the supercoils? Do you need to add ATP to the system?