What is the definition of a dominant trait in biology? What is the difference between biology and AP biology? What is the difference between molecular biology and cell biology?
DNA gyrase, often referred to simply as gyrase, is an enzyme that relieves strain while double-strand DNA is being unwound by helicase. It is also known as DNA topoisomerase II. This causes negative supercoiling of the DNA. Bacterial DNA gyrase is the target of many antibiotics, including nalidixic acid, novobiocin, and ciprofloxacin.
Supercoiled DNA tends to run faster than the same size plasmid not supercoiled. This is not very predictable as sometimes the DNA can take on different shapes, and sometimes plasmids can become interlinked with other plasmids, like a chain. This doesn't generally happen with common cloning plasmids in common E coli.