Aminoacyl tRNA (also called charged tRNA) is formed through a two-step process catalyzed by aminoacyl-tRNA synthetases.
Step 1: Amino Acid Activation (Adenylation)
The first step involves activating the amino acid by attaching it to AMP (adenosine monophosphate). This reaction forms aminoacyl-AMP and releases pyrophosphate (PPi).
Amino Acid + ATP → Aminoacyl-AMP + PPi
Step 2: tRNA Charging (Transfer)
In the second step, the activated amino acid (aminoacyl-AMP) is transferred to the appropriate tRNA molecule. The amino acid is attached to the 3' end of the tRNA, specifically to the terminal adenosine residue. This reaction releases AMP.
Aminoacyl-AMP + tRNA → Aminoacyl-tRNA + AMP
In summary, aminoacyl-tRNA formation involves the adenylation of an amino acid followed by the transfer of the activated amino acid to the correct tRNA molecule, a process essential for protein synthesis.
