Participation of the host protein(s) in the morphogenesis of bacteriophage P22

Spontaneous mutants of S. typhimurium resistant to thiolutin are conditionally non-permissive for phage P22 development (Joshi and Chakravorty 1979). At 40 degree C non-infective phage particles are produced. Phage development in two nonpermissive hosts (18/MC4 and 153/MC4) has been studied in detail. The steps at which the phage morphogenesis is interfered with differ in the two mutants. The electron micrograph of the particles produced in the mutant 18/MC4 reveals the presence of normal-looking particles; these particles contain phage DNA, adsorb to the permissive host but fail to inject their DNA. The particles produced in the mutant 153/MC4 which fail to adsorb to the host are found to be tail fibre-less. These observations indicate the involvement of host protein(s) in phage P22 morphogenesis.