Inactivation of Ribosomes <i>In Vitro</i> by Colicin E ₃

Abstract

Cell-free protein synthesizing extracts incubated with purified preparations of colicin E(3) showed a marked decrease of their protein synthesizing activity. Incubation of ribosomes prepared from S-30 extracts with E(3) resulted in their inactivation. Their 16S RNA was found to lose a terminal fragment, similar in size to the fragment released upon in vivo treatment with E(3). Extracts derived from colicinogenic strains are resistant to the action of E(3)in vitro.