Elongation factors

Definition

Elongation factors are proteins that play crucial roles during the elongation phase of protein synthesis, facilitating the addition of amino acids to the growing polypeptide chain. They assist in the accurate and efficient translation of mRNA into a functional protein by promoting the binding of aminoacyl-tRNA to the ribosome, ensuring that the correct amino acids are incorporated in the right sequence. These factors are vital for maintaining the fidelity and speed of translation, which is essential for proper cellular function.

5 Must Know Facts For Your Next Test

1. Elongation factors can be divided into two main types: EF-Tu, which helps in delivering aminoacyl-tRNA to the ribosome, and EF-G, which facilitates translocation of the ribosome along the mRNA strand.
2. These factors help increase the speed of translation by ensuring that amino acids are added quickly and accurately to the growing polypeptide chain.
3. The interaction between elongation factors and the ribosome is critical for preventing errors in protein synthesis, thereby maintaining protein integrity.
4. Elongation factors undergo conformational changes during their function, which are essential for their activity and interactions with other components of the translation machinery.
5. Inhibition of elongation factors can lead to decreased protein synthesis and has been a target for various antibiotics that disrupt bacterial translation.

Review Questions

• How do elongation factors contribute to the accuracy of protein synthesis?
  • Elongation factors enhance the accuracy of protein synthesis by ensuring that the correct aminoacyl-tRNA molecules are brought to the ribosome. This is primarily achieved by elongation factor Tu (EF-Tu), which binds to aminoacyl-tRNA and delivers it to the A-site of the ribosome. The factor checks for proper codon-anticodon pairing before allowing peptide bond formation, thus minimizing mistakes in translation.
• Discuss the roles of different elongation factors during the elongation phase of translation.
  • Different elongation factors play specific roles during translation's elongation phase. For example, EF-Tu is responsible for escorting aminoacyl-tRNA to the ribosome, while EF-G facilitates ribosomal translocation after peptide bond formation. The coordinated action of these factors allows for rapid progression through the mRNA while ensuring high fidelity in protein synthesis.
• Evaluate how inhibiting elongation factors can affect cellular processes and how this knowledge is applied in antibiotic development.
  • Inhibiting elongation factors disrupts protein synthesis, which can have severe consequences for cellular processes such as growth and metabolism. This understanding has been pivotal in developing antibiotics that target bacterial elongation factors. By selectively inhibiting these proteins, antibiotics can effectively halt bacterial growth without affecting eukaryotic cells, making them valuable tools in combating bacterial infections.

Related terms

aminoacyl-tRNA: A molecule formed by attaching an amino acid to its corresponding tRNA, ensuring that the correct amino acid is brought to the ribosome during translation.

ribosome: A molecular machine made up of ribosomal RNA and proteins, responsible for translating mRNA into polypeptides during protein synthesis.

transcription: The process of synthesizing RNA from a DNA template, which precedes translation and sets the stage for protein production.