Is energy used in translation termination?

Is energy used in translation termination?

• A. Yes
• B. No
• C. Not specified
• D. Only in prokaryotes

Answer: (A)

Energy is used in translation termination because the stop-codon recognition is coupled to GTP-hydrolyzing release factors that drive the final steps. When a stop codon is in the A site, release factors bind and promote the cleavage of the bond between the polypeptide and tRNA; more importantly, GTP hydrolysis by these factors (RF3 in bacteria or eRF3 in eukaryotes) powers the release factor turnover and ribosome recycling. So the termination process is not energy-free—the GTP coming from these factors provides the necessary energy to finish translation and reset the ribosome for another round. The other options misstate this: termination does involve energy in these GTPase-driven steps, and this occurs in both prokaryotes and eukaryotes.

Energy is used in translation termination because the stop-codon recognition is coupled to GTP-hydrolyzing release factors that drive the final steps. When a stop codon is in the A site, release factors bind and promote the cleavage of the bond between the polypeptide and tRNA; more importantly, GTP hydrolysis by these factors (RF3 in bacteria or eRF3 in eukaryotes) powers the release factor turnover and ribosome recycling. So the termination process is not energy-free—the GTP coming from these factors provides the necessary energy to finish translation and reset the ribosome for another round. The other options misstate this: termination does involve energy in these GTPase-driven steps, and this occurs in both prokaryotes and eukaryotes.