The action of ribonuclease on phage protein synthesis by an induced lysogenic Bacillus megaterium culture

Abstract

Ribonuclease selectivily inhibits phage protein synthesis in ultraviolet-induced lysogenic Bacterium megaterium. The sooner the enzyme is added after induction, the more extensive is the inhibition. On the other hand, the number of infectious phage particles produced depends on the amount of phage protein already synthesised before RNase is added. This indicates that the phage proteins synthesized in the presence of RNase are not integrated into normal infectious particles. Nevertheless, these proteins are assembled into phage-like particles of normal aspect containing DNA. The fact that they are not infectious seems to be related to their defective fixation onto the host bacteria. These facts may be taken into account by a hypothesis according to which RNase modifies the structure of RNA molecules that would function as templates in phage protein synthesis.