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.
Supercoiling simply means the coiling of an already coiled structure (such as DNA). DNA is coiled around itself for several reasons. The three dimensional structure of DNA affects its function. The coiling can have positive or negative effects on gene expression.