Question

The role of enzyme E synthesized by phage $\phi$X174 during host infection is to

• A. block peptidoglycan synthesis
• B. enhance synthesis of viral +RNA
• C. inhibit lipid metabolism
• D. stimulate dsDNA replication

Hint:

Phage lysis proteins often target bacterial cell wall biosynthesis to burst the host cell.

Answer 1

The Correct Option is A

Step 1: Understanding enzyme E of phage $\phi$X174.
Phage $\phi$X174 infects bacteria and produces an enzyme called "E protein." This protein functions as a lysis enzyme that stops bacterial cell wall synthesis by preventing peptidoglycan formation.
Step 2: Evaluating the options.
(A) Correct — enzyme E inhibits peptidoglycan synthesis, causing host cell lysis.
(B) Incorrect — it does not affect viral RNA synthesis directly.
(C) Incorrect — lipid metabolism is not targeted.
(D) Incorrect — dsDNA replication is unrelated to this enzyme.
Step 3: Conclusion.
Enzyme E blocks peptidoglycan synthesis, leading to host cell lysis and phage release.