What is the immediate molecular consequence of tetracycline binding to the bacterial 30S subunit?

• A. Steric blockage of aminoacyl-tRNA entry into the A site, preventing addition of new amino acids to the growing peptide chain.
• B. Permanent cross-linking of ribosomal proteins that leads to ribosome degradation by cellular proteases.
• C. Induction of mRNA cleavage at the decoding site, resulting in prematurely truncated messages that halt translation.
• D. Inhibition of the ribosomal peptidyl transferase center on the 50S subunit, preventing peptide bond formation between amino acids.

Answer: (A)