<prompt> Fluoroquinolones act on -DNA histone proteinsDNA gyraseCampmRNA polymerise  <response>: Ans. is b i.e., DNA gyrase o Fluoroquinolones including ciprofloxacin inhibit DNA gyrase and topoisomerase IV. For gram negative bacteria, the primary target is DNA gyrase, while topoisomerase IV is inhibited in gram positive bacteria. 