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In a study involving a cell-free translation system from coli, the polyribonucleotide AUGUUUUUUUUUUUU directs the synthesis of the oligopeptide fMet-Phe-Phe-Phe-Phe. In the presence of a new class of translation-targeting antibiotics that bind to the large ribosomal subunit, the ribosomal complex forms, the initiator tRNA binds the mRNA, the second tRNA enters the A site of the ribosome, but no peptide bonds form. Which of the following is a likely function of these new antibiotics?

a. Blocks peptidyl transferase activity
b. Inhibits tRNA aminoacyl synthetase function
c. Inhibits ribosomal translocation along the mRNA
d. Prevents anticodon base-pairing with the codon
e. Blocks binding of the Shine-Dalgarno box to the rRNA

User Kekoa
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1 Answer

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15 votes

Answer:

c. Inhibits ribosomal translocation along the mRNA.

Step-by-step explanation:

Initiator tRNA is thought to bind directly to P-site of small ribosomal sub unit. These tRNA are positioned at P site and remain attached to tRNA located at this site. Initiation factor helps to mediate this event.

User Laridzhang
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