Question

Why is proofreading necessary during aminoacylation?

Short answer

Proofreading is necessary during aminoacylation as it increases the accuracy of the amino acids attached to the tRNA.

Step-by-step solution

Charging tRNA

The charging of tRNA or aminoacylation is a two-step process where the first step involves the activation of amino acids and then the second, the transfer of the activated amino acid moiety to tRNA.

Proofreading

The aminoacyl tRNA synthetase then hydrolyzes the mismatched amino acids either before transferring them to the tRNA or after they are wrongly transferred. It is therefore water-mediated lysis of the wrongly charged tRNA and activated amino acids.