Photoassimilation of acetate and the biosynthesis of amino acids by Chlorobium thiosulphatophilum

by the formation of amino acyl-RNA.A method is described for the separation of amino acyl-RNA from enzyme reaction mixtures by chromato- graphy on DEAE-cellulose.3. The pyrophosphate-exchange reaction cata- lysed by the synthetases from the protein-body preparation showed an apparent inhibition with added ATP.The pyrophosphate exchange cata- lysed by the enzymes from the supernatant pre- paration was almost completely dependent on ATP and stimulated by the addition of ATP.The formation of amino acyl-RNA by enzyme preparations from both the protein-body and supernatant pre- parations was stimulated by the addition of ATP.4. An enzyme fraction obtained from the protein-body preparation after treatment with ultrasonic vibration catalysed the incorporation of amino acids into amino acyl-RNA and soluble protein.5. The localization of enzymes and RNA associ- ated with the initial stages of protein synthesis in the two preparations from wheat endosperm, and the significance of these findings in relation to the independent synthesis of storage and cytoplasmic proteins of wheat endosperm, is discussed.