Translation of R-17 RNA Fragments

Examination of the events during infection of cells by RNA phages reveals phemomena that are surprisingly complex for a virus that has only enough information to code for three to four proteins. The coat protein is synthesized at a rapid rate through most of the infectious cycle making it the predominant product. In contrast, the RNA synthetase is made at early times but not at late times (Viñuela et al., 1967a; Nathans et al., 1969). Since the RNA genome is itself messenger, the RNA phages present a unique opportunity to study translation of a polycistronic messenger. As first shown by Nathans et al. (1962) the major product of f2 directed in vitro protein synthesis is the coat protein, as is observed in vivo. Translation of the RNA synthetase cistron in vitro (Capecchi, 1966; Eggen et al., 1967; Viñnuela et al., 1967b; Lodish, 1968) can be efficiently repressed by the addition...