Charging of tRNA, also known as aminoacylation, refers to the process of attaching an amino acid to its corresponding transfer RNA (tRNA). This crucial step is also called amino acid activation.
Essentially, tRNA charging ensures that each tRNA molecule carries the correct amino acid, allowing for accurate protein synthesis during translation.
Here's a breakdown:
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The Goal: To covalently link a specific amino acid to its cognate tRNA molecule.
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The Enzyme: Aminoacyl-tRNA synthetases (aaRSs) are responsible for catalyzing this reaction. Each aaRS is highly specific for a particular amino acid and its corresponding tRNA(s).
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The Process (Simplified):
- The amino acid is activated by reacting with ATP, forming an aminoacyl-AMP intermediate and releasing pyrophosphate (PPi).
- The activated amino acid is then transferred to the 3' end of the tRNA molecule.
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Why it Matters: Without correct tRNA charging, the ribosome would incorporate the wrong amino acids into the growing polypeptide chain, leading to non-functional or misfolded proteins.
| Term | Definition |
|---|---|
| tRNA charging | The process of attaching an amino acid to its corresponding tRNA. |
| Aminoacylation | Synonym for tRNA charging. |
| Aminoacyl-tRNA | The tRNA molecule with its amino acid attached; ready for protein synthesis. |
| aaRS | Aminoacyl-tRNA synthetase; the enzyme catalyzing tRNA charging. |
