The Enzymic Synthesis of Amino Acyl Derivatives of Ribonucleic Acid I. THE MECHANISM OF LEUCYL-, VALYL-, ISOLEUCYL-, AND METHIONYL RIBONUCLEIC ACID FORMATION”

The enzymic formation of enzyme-bound amino acyl adenylates from adenosine triphosphate and amino acid (Equation 1) has been recognized for several years (l-8) and enzymes specific for certain of the amino acids have been isolated in a number of laboratories (2, 9, 10). These same enzymes are now known (11-15) to catalyze a second reaction involving the transfer of the amino acyl moiety from the adenosine phosphate moiety to a specific type of ribonucleic acid (Equation 2). The over-all reaction catalyzed by such amino acyl ribonucleic acid synthetasesl is summarized in Equation 3.