Question
Which of the following drugs acts by inhibiting the transcription of DNA to RNA?
A. Rifampicin
B. Nitrofurantoin
C. Ciprofloxacin
D. Novobiocin
Show Answer
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Correct Answer » A
Explanation
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Ans: A. Rifampicin
Overall inhibition of RNA synthesis by rifampicin is caused by a destabilizing effect on the binding of the intermediate oligonucleotides to the active enzyme-DNA complex.
Rifampicin itself can only interact specifically with RNA polymerase if the enzyme is free or in a binary complex with DNA.