Ciprofloxacin acts on: (A) DNA histone proteins, (B) DNA gyrase, (C) Camp, (D) mRNA polymerase
Answer is B. Ans. is 'b' i.e., DNA gyrase Major mechanism of action of fluoroquinolone is inhibition of bacterial enzyme DNA gyrase.Recent evidence indicates that in gram positive bacterias, the major target is topoisomerase IV.So greater affinity for topoisomerase IV may confer higher potency against gram positive bacteria.