Resistance to acyclovir is most commonly due to mutation in a viral gene that encodes a protein that:: (A) Conves viral RNA into DNA, (B) Phosphorylates acyclovir, (C) transpos acyclovir into the cell, (D) Transpos acyclovir out of the cell
Answer is B. (Ref: KDT 6/e p768) Nucleoside/tide analogues (like acyclovir) act by conveing to NTPs. First phosphorylation step occurs inside the virs and resistance occurs if there is mutation in this gene.