Release Factor

Definition

The release factor is a protein involved in the termination of protein synthesis during the translation process. It recognizes specific stop codons in the mRNA sequence and facilitates the release of the newly synthesized polypeptide chain from the ribosome.

5 Must Know Facts For Your Next Test

1. The release factor recognizes the stop codons UAA, UAG, or UGA in the mRNA sequence, signaling the ribosome to terminate translation.
2. The release factor binds to the stop codon and induces a conformational change in the ribosome, allowing the completed polypeptide chain to be released.
3. There are two main types of release factors: RF1, which recognizes the UAA and UAG stop codons, and RF2, which recognizes the UAA and UGA stop codons.
4. The release factor interacts with the ribosome's peptidyl transferase center, which catalyzes the hydrolysis of the bond between the polypeptide chain and the tRNA, releasing the completed protein.
5. Proper functioning of the release factors is crucial for ensuring the accurate termination of protein synthesis and the release of the final polypeptide chain.

Review Questions

• Explain the role of the release factor in the translation of mRNA into a polypeptide chain.
  • The release factor plays a critical role in the termination of protein synthesis during the translation process. It recognizes specific stop codons (UAA, UAG, or UGA) in the mRNA sequence and binds to the ribosome, inducing a conformational change that allows the completed polypeptide chain to be released from the tRNA and the ribosome. This ensures the accurate termination of translation and the release of the final protein product.
• Describe the different types of release factors and their specific functions.
  • There are two main types of release factors involved in protein synthesis: RF1 and RF2. RF1 recognizes the UAA and UAG stop codons, while RF2 recognizes the UAA and UGA stop codons. Both release factors bind to the ribosome's peptidyl transferase center, catalyzing the hydrolysis of the bond between the polypeptide chain and the tRNA, thereby facilitating the release of the completed protein. The specific recognition of different stop codons by the release factors ensures the accurate termination of translation for a wide range of mRNA sequences.
• Analyze the importance of the release factor in the overall process of protein biosynthesis.
  • The release factor is a crucial component in the translation of mRNA into a functional protein. Without the proper functioning of the release factor, the polypeptide chain would not be able to be released from the ribosome, preventing the completion of protein synthesis. The release factor ensures the accurate termination of translation by recognizing specific stop codons and inducing the necessary conformational changes in the ribosome. This allows the finished polypeptide chain to be released, enabling it to fold into its native structure and perform its intended biological functions. The release factor's role in the final stage of protein biosynthesis is essential for the proper expression of genetic information and the maintenance of cellular homeostasis.

Related terms

Stop Codon: A triplet of nucleotides in the mRNA sequence that signals the ribosome to stop translating the genetic code and release the completed polypeptide chain.

Polypeptide Chain: The linear sequence of amino acids that is synthesized during the translation process, which will fold into a functional protein.

Ribosome: The cellular organelle responsible for the synthesis of proteins, where the translation of mRNA into a polypeptide chain occurs.