Noun
gyrase (countable and uncountable, plural gyrases)
English Wikipedia has an article on:gyraseWikipedia
(biochemistry) An enzyme that supercoils DNA.
For many gram-negative bacteria, DNA gyrase is the target, whereas topoisomerase IV is the target for many gram-positive bacteria. Source: Internet
Finally, mutations at key sites in DNA gyrase or topoisomerase IV can decrease their binding affinity to quinolones, decreasing the drugs' effectiveness. Source: Internet