Yeast phenylalanyl-tRNA synthetase: evidence for the formation of ADP by phosphorolysis of enzyme-bound aminoacyladenylate
Guédon, G.; Ebel, J.P.; Remy, P.
Biochimie 69(11-12): 1175-1181
ADP and Ap3A are synthesized by the yeast phenylalanyl-tRNA synthetase, according to reaction pathways similar to the pyrophosphorolysis of the intermediate aminoacyladenylate or to the one leading to Ap4A synthesis. The enzyme-bound phenylalanyladenylate reacts with inorganic phosphate or ADP to yield, respectively, ADP or Ap3A. The rate of synthesis is strongly stimulated by Zn2+. This new phosphorolysis activity accounts for the complex pattern of bisnucleoside polyphosphate syntheses starting from ATP.