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The attachment of amino acid to the tRNA during translation is referred to as aminoacylation. The tRNA with the correct amino acid attached is charged aminoacyl-tRNAs, for instance, ´¡±ô²¹â€“t¸é±·´¡^Ala and ³Ò±ô²Ô–t¸é±·´¡^Gln. On the other hand, tRNA with incorrect amino acids is denoted as mischarged aminoacyl-tRNA, for instance, ³Ò±ô²Ô–t¸é±·´¡^Ala and ´¡±ô²¹â€“t¸é±·´¡^Gln.

The appropriately charged tRNAs (Ala-tRNA^Ala and Gln-tRNA^Gln bind to EF-Tu with almost the same affinity and are therefore transported to the ribosomal A site with around equal efficiency.The data suggests that the mischarged Ala-tRNA^Gln binds to EF-Tu considerably more loosely (260), exhibiting that it may separate from EF-Tu before reaching the ribosome. While, EF-Tu binds to the mischarged Gln-tRNA^Alaconsiderably more firmly (0.05), suggesting that EF-Tu may not be able to separate from it at the ribosome.

These findings imply that either a higher or lower binding affinity may influence EF-Tu capacity to do its task. The lower and higher affinity would reduce the rate at which mischarged aminoacyl-tRNAs bind to the ribosomal A site during translation.