Phenylalanyl-tRNA and Seryl-tRNA from Synthetases Baker's Yeast. Substrate Specificity with Regard to ATP Analogs and Mechanism of the Aminoacylation Reaction

Abstract

Eighteen analogs of ATP have been tested in the aminoacylation reaction of phenylalanyl‐tRNA and seryl‐tRNA synthetases from baker's yeast. Four compounds. are substrates for phenylalanylLRNA syntiteiase, live for seryl‐tRNA synthetase, one compound is an inhibitor for both enzymes; their K_m and K_i and V values have been determined. The substrate specificity shows that for the catalytic action of both enzymes with these substrates positions 6, 7, 8 and 9 of the purine moiety and positions 2′ and 3′ of the ribose moiety are important.