EF-G

Definition

EF-G, or elongation factor G, is a protein that plays a crucial role in the translation process within cells by facilitating the translocation of the ribosome along the mRNA during protein synthesis. This factor is essential for the movement of tRNA from the A-site to the P-site of the ribosome, ensuring that amino acids are added correctly to the growing polypeptide chain. EF-G also hydrolyzes GTP to GDP, providing the necessary energy for this translocation process.

5 Must Know Facts For Your Next Test

1. EF-G binds to the ribosome during the elongation phase of translation, where it promotes the movement of tRNA and mRNA to facilitate proper peptide bond formation.
2. The translocation mediated by EF-G is essential for maintaining the accuracy and efficiency of protein synthesis, allowing ribosomes to move along mRNA without errors.
3. EF-G is a GTP-binding protein, and its activity relies on the hydrolysis of GTP to GDP, which acts as a switch to control its function during translation.
4. Inhibitors targeting EF-G can effectively halt bacterial protein synthesis, making it a potential target for antibiotic development.
5. Different organisms have evolved variations of EF-G, with bacteria and eukaryotes having distinct versions that reflect their specific translation machinery.

Review Questions

• How does EF-G facilitate translocation during the translation process?
  • EF-G facilitates translocation by binding to the ribosome and promoting the movement of tRNA from the A-site to the P-site. This action helps ensure that the ribosome progresses along the mRNA correctly, allowing for accurate addition of amino acids to the growing polypeptide chain. The process requires energy derived from GTP hydrolysis, which allows EF-G to function effectively during this critical phase of protein synthesis.
• Discuss the role of GTP hydrolysis in the function of EF-G and its importance in translation.
  • GTP hydrolysis is vital for EF-G's function as it provides the necessary energy for translocation during translation. When EF-G binds to the ribosome in its GTP-bound form, it undergoes a conformational change that facilitates movement along mRNA. After hydrolyzing GTP to GDP, EF-G releases from the ribosome, allowing it to reset and prepare for subsequent rounds of translation. This mechanism ensures that protein synthesis occurs efficiently and accurately.
• Evaluate how targeting EF-G could be beneficial in developing new antibiotics and its implications for bacterial protein synthesis.
  • Targeting EF-G offers a promising strategy for developing new antibiotics since inhibiting this factor can effectively stop bacterial protein synthesis. By disrupting EF-G's function, these antibiotics would prevent bacteria from accurately synthesizing proteins essential for their growth and survival. This approach not only highlights the critical role of EF-G in maintaining bacterial life but also underscores the potential for designing drugs that exploit specific differences between bacterial and eukaryotic translation machinery, potentially reducing side effects on human cells.

Related terms

Ribosome: A complex molecular machine found within all living cells that synthesizes proteins by translating messenger RNA (mRNA) into polypeptide chains.

Translation: The process by which ribosomes synthesize proteins using the genetic information encoded in mRNA, involving initiation, elongation, and termination phases.

GTPase: An enzyme that hydrolyzes GTP to GDP, which is a crucial mechanism for energy transfer and signaling in various cellular processes, including translation.