Question

You are attempting to determine which step of prokaryotic translation a new antibiotic inhibits. You have determined that the antibiotic interacts with a translational factor but need to identify which one. If the new antibiotic interferes with elongation, which of the following factors could be a potential site of action?

A) IF3 interaction with an aminoacyl tRNA
B) EF-Tu placement of N-formylmethionine onto the ribosome
C) EF-Tu interaction with an aminoacyl tRNA
D) EF-Ts translocation of tRNAs from the A site to the P site
E) All of these could be potential sites of action.

Answer 1

An antibiotic that interferes with prokaryotic translation elongation could potentially target EF-Tu, which is involved in delivering aminoacyl tRNAs to the ribosome, or EF-Ts, which helps regenerate active EF-Tu.

Step-by-step explanation:

In prokaryotic translation, the elongation phase involves several key factors that facilitate the addition of amino acids to the growing polypeptide chain. One of these factors is EF-Tu, which binds to the charged aminoacyl tRNA and GTP. The EF-Tu-GTP-aminoacyl tRNA complex then delivers the aminoacyl tRNA to the A (aminoacyl) site of the ribosome.

Once the correct match of tRNA anticodon and mRNA codon is ensured, GTP is hydrolyzed, causing a conformational change in EF-Tu that leads to its release from the ribosome and the binding of the aminoacyl tRNA in the A site. EF-Ts is involved in the regeneration of active EF-Tu by promoting the exchange of GDP with GTP. Considering the role of these factors, the potential sites of action for an antibiotic that interferes with elongation could include: