Index >>Ribose Nucleic Acids >>Specificity of  Tranfer RNA - tRNA

Specificity of  Tranfer RNA - tRNA - Two important steps in translation during protein synthesis are the activation of amino acids and the transfer of amino acids to tRNAs. Each amino acid has a specific activating enzyme tRNA aminoacyl synthetase. Thus there are 20 different tRNA aminoacyl synthetases for the 20 common amino acids found in proteins.

Some tRNA synthetases can activate more than one amino acid, i.e. they show only a limited substrate specificity. Thus isoleucine tRNA synthetase can also activate L valine, and valine tRNA synthetase can also react with threonine. The enzymes, however, recognize only a specific set of, tRNAs as substrates.