Studies on the interaction of subviral particles of the bacteriophage [phi]X174 with protoplasts of Escherichia coli

Interaction of Subviral Particles of Bacteriophage [phi]X174 with Protoplasts of Escherichia coli. Part I: Infection of Protoplasts of Escherichia coli by Subviral Particles of Bacteriophage [phi]X174. G. D. Guthrie and R. L. Sinsheimer, J. Mol. Biol., (1960), 2, 297-305. Infection of protoplasts of E. coli leading to the production of mature phage can occur with subviral particles of phage [phi]X174, including the purified DNA of the phage. Methods for obtaining the proper conditions for infection are described. Results of experiments describing the characteristics of the infection and the nature of the subviral particles causing the infection are presented. Evidence is presented that net synthesis of mature [phi]X174 can be obtained from infection of protoplasts by purified [phi]X174 DNA. Part II: Initial Studies on Protoplasts and [phi]X-DNA as a system for investigating virus replication. G. D. Guthrie (unpublished thesis research). Further investigations on the interaction of [phi]X-DNA with protoplasts are described. General techniques to be employed in using the system for the study of the replication of virus are outlined. Data from investigations on the initial "infection" process of [phi]X-DNA are presented. From these data, factors influencing the level of infection are discussed and a simple mathematical relationship relating these parameters to the infection is proposed.