At which specific site on a tRNA molecule does the cognate amino acid become covalently attached?
Answer and explanation
Correct answer: B. CCA sequence at the 3' hydroxyl terminus
- Step 1: Aminoacyl-tRNA synthetase charges tRNA by attaching an amino acid to the terminal adenosine. Step 2. The attachment occurs via an ester bond to the 3' hydroxyl group of the conserved 3'-CCA sequence. Answer: CCA sequence at the 3' hydroxyl terminus. Why not the others: 5' phosphate end is the start of polynucleotide; anticodon loop pairs with mRNA; variable loop provides structural recognition.
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