Question

The antibiotic paromomycin binds to a ribosome and induces the same conformational changes in 16S rRNA residues A1492 and A1493 as are induced by codon–anticodon pairing (Fig. 27-32). Propose an explanation for the antibiotic effect of paromomycin.

Short answer

The conformational changes induced by the antibiotic paromomycin in the 16S rRNA residuesdisturb the induced-fit mechanism that regulates the decoding process. Thus, the antibiotic disrupts the translation process, and as a result, protein synthesis is inhibited.

Step-by-step solution

Paromomycin

Paromomycin is an antibiotic used to treat parasitic infections such as amebiasis.Other infections treated by this antibiotic are tapeworm infection, giardiasis, and leishmaniasis. It is also known as monomycin and aminosidine.

Action of antibiotic

Antibiotic kills or inhibits bacteria growth by disrupting the essential bacterial processes or structures. They affect cell wall synthesis, nucleic acid synthesis, protein synthesis, and so on. Paromomycin is an antibiotic that affects protein synthesis.

Antibiotic effect of paramomycin

The antibiotic paromomycin binds to h44 of 16s rRNA and induces conformational changes in A1492 and A1493 residues that cause them to flip out. They flip out to face the A-site codon-anticodon helix, and paromomycin can maintain the 30S subunit's closed shape. This disturbs the decoding controlling induced fit mechanism, affecting the translation. As a result, protein synthesis is inhibited.