Structure of the lipid-containing bacteriophage PRD1: disruption of wild-type and nonsense mutant phage particles with guanidine hydrochloride.

The lipid-containing bacteriophage PRD1 was disrupted, and the subviral particles were studied. Guanidine treatment released two phage proteins (P3 and P5). These proteins form the polyhedral capsid. The remaining phage proteins were associated with the phage membrane vesicle. The vesicle was capable of forming a tubular structure. The isolated phage membrane vesicles aggregated readily. We found that aggregation and tube formation were associated with specific phage proteins (P11 and P18, respectively) by using protease treatment and an analysis of nonsense mutant phage particles. In addition, the possibility that free vesicles might be precursors to empty virions was studied.