How DNA is supercoilded and relaxed Enzyme involved in supercoiling (in bacteria) DNA gyrase(旋转酶): DNA Topoisomerase I(DNA拓朴异构酶I) Enzyme involved in removing supercoiling DNA gyrase DNA TopOISOmerase I Two antibiotics(Nalidixic acid and Novobiocin) inhibit the action of DNAHow DNA is supercoilded and relaxed Enzyme involved in supercoiling (in bacteria): – DNA gyrase (旋转酶）： • DNA Topoisomerase II (DNA拓朴异构酶II) Enzyme involved in removing supercoiling: – DNA gyrase: • DNA Topoisomerase I Two antibiotics (Nalidixic acid and Novobiocin) inhibit the action of DNA