Initial stages in the incorporation of amino acids into protein in rat-liver mitochondria

Abstract

An extract of mitochondria was prepared which could replace cell sap in a system in vitro by stimulating the incorporation of amino acids into ribosomal protein. A pH 5 precipitate prepared from the mitochondrial extract could replace the whole extract. In the system containing ribosomes and mitochondrial extract GTP stimulated the incorporation of amino acids into protein, and puromycin was inhibitory. CTP and UTP were without significant effect. No appreciable incorporation of amino acid into the RNA of the mitochondrial extract was detected. The possible role of the soluble portion cf the mitochondria in the incorporation of amino acids into protein in isolated mitochondria is discussed.