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.
DNA supercoiling refers to the over-or under-winding of a DNA strand, and is an expression of the strain on that strand. Supercoiling is important in a number of biological processes, such as compacting DNA. Additionally, certain enzymes such as topoisomerases are able to change DNA topology to facilitate functions such as DNA replication or transcription.