regulation of translational fidelity

Definition

Target type: biologicalprocess

Any process that modulates the ability of the translational apparatus to interpret the genetic code. [GOC:dph, GOC:tb]

Translational fidelity refers to the accuracy of protein synthesis, ensuring that the correct amino acids are incorporated into the growing polypeptide chain according to the genetic code. This intricate process is tightly regulated by various mechanisms, ensuring the production of functional proteins.

Key players in translational fidelity regulation include:

1. **tRNA Selection:** The accuracy of amino acid incorporation is largely dependent on the precise recognition of cognate tRNAs by the ribosome. This process involves multiple steps, including:
* **Decoding Center:** The ribosome's decoding center, a highly conserved region within the small ribosomal subunit, interacts with the tRNA's anticodon loop to ensure proper codon-anticodon pairing.
* **Kinetic Proofreading:** The ribosome employs a kinetic proofreading mechanism, whereby incorrect tRNA binding is rapidly rejected due to its lower affinity for the decoding center.
* **Quality Control Factors:** Elongation factors, such as EF-Tu (in bacteria) or eEF1α (in eukaryotes), bind to charged tRNAs and facilitate their entry into the ribosome. These factors also contribute to proofreading by ensuring that only correctly paired tRNAs are delivered to the A site of the ribosome.
2. **Ribosome Structure and Function:** The intricate structure of the ribosome itself plays a crucial role in translational fidelity.
* **Ribosomal Subunit Association:** The correct association of the small and large ribosomal subunits is essential for proper mRNA binding and tRNA decoding.
* **Ribosomal Conformation:** The ribosome undergoes conformational changes during translation, ensuring the correct positioning of tRNAs and mRNA within the ribosomal tunnel.
* **Ribosomal Modifications:** Modifications of ribosomal RNA (rRNA) can influence tRNA binding affinity and decoding accuracy.
3. **mRNA Quality Control:** The quality of mRNA can impact translational fidelity.
* **mRNA Stability:** Stable mRNA molecules ensure that the correct genetic information is translated.
* **mRNA Structure:** The secondary and tertiary structure of mRNA can influence ribosome binding and translation initiation.
* **mRNA Degradation:** Defective or damaged mRNAs are subject to degradation mechanisms that prevent the synthesis of aberrant proteins.
4. **Translation Factors:** A variety of translation factors contribute to the regulation of translational fidelity.
* **Elongation Factors:** These factors facilitate the movement of the ribosome along the mRNA and ensure the proper positioning of tRNAs.
* **Termination Factors:** These factors recognize stop codons and trigger the release of the newly synthesized polypeptide chain from the ribosome.
* **Ribosome Recycling Factors:** These factors dissociate the ribosomal subunits after translation termination and prepare them for new rounds of protein synthesis.

The tight regulation of translational fidelity is essential for cell viability and function. Errors in protein synthesis can lead to the production of non-functional or even toxic proteins, contributing to various diseases. As a result, cells have evolved sophisticated mechanisms to ensure the accuracy of this crucial process.'
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Proteins (1)

Compounds (2)