Does protein synthesis use ATP?
Energy for binding the amino acid to tRNA comes from ATP conversion to adenosine monophosphate. Activation of amino acids requires energy in the form of ATP and occurs in a two step reaction catalyzed by the aminoacyl-tRNA synthetases. First the enzyme attaches the amino acid to the a-phosphate of ATP with the concomitant release of pyrophosphate. This is termed an aminoacyl-adenylate intermediate. In the second step the enzyme catalyzes transfer of the amino acid to either the 2′- or 3′-OH of the ribose portion of the 3′-terminal adenosine residue of the tRNA generating the activated aminoacyl-tRNA. Although these reaction are freely reversible, the forward reaction is favored by the coupled hydrolysis of PPi.
