Question

Acyclovir is a drug used to treat viral infection by impairing its replication. Why will it not effect bacterial replication as well?

(a) Bacteria under viral attack don’t replicate

(b) Viral polymerase binds to it and thus can’t perform its function

(c) Virus uses it in a polymerization

(d) Cellular mechanism deactivates it

I had been asked this question during a job interview.

The above asked question is from DNA Replication Prokaryotes in chapter DNA Replication of Cytogenetics

Answer 1

Correct answer is (c) Virus uses it in a polymerization

For explanation: Acyclovir is a GMP analogue that cellular mechanism activates to GTP analogue, which the virus uses as a substrate while polymerizing. However, as it lacks 3’-OH it terminates the replication process. Thus, cellular processes activate this drug, yet its specificity to viral polymerase protects the cell.