Infectious nucleic acids of Escherichia coli bacteriophages : XII. Fate of double-stranded bacteriophage ribonucleic acid in Escherichia coli spheroplasts

Abstract

Double-stranded replicative bacteriophage RNA (i.e. the completely double-stranded replicative form, termed RF, and the partially single-stranded replicative intermediate form, termed RI) were isolated from M12 RNA phage-infected Escherichia coli bacteria and subsequently mixed with E. coli spheroplasts. RF and RI adsorb to, and penetrate into, spheroplasts in amounts similar to those found with single-stranded phage RNA. No evidence was found for intracellular destruction of RF and RI by ribonuclease III, whereas in polysomal extracts RNase III converts double-stranded RNA rapidly to a form, which is still acid-precipitable but RNase-sensitive. Phage-specific polysomes have been detected in RI- and single-stranded M12 RNA-infected spheroplasts; however, RF could not be found in polysomes. The likelihood that the failure to be translated is the primary cause of the non-infectivity of double-stranded phage RNA in E. coli spheroplasts will be discussed.