Structures of the tailed bacteriophages that infect Gram-positive bacteria.

Productive virus infection depends upon delivery of viral genomic material into the host cell cytoplasm. The tails of bacteriophages recognize host cells and mediate host cell wall and membrane penetration. Recent cryo-electron microscopy studies have revealed near atomic-resolutions structures of the entire or almost entire bacteriophage particles of model systems including phi29, P22, P68, and T4. These structures allow comparisons between not only different states of the same phage but also between distantly related phages. In this review, we summarize the findings from recent structural studies of the bacteriophages that target Gram-positive bacteria, for a better understanding of the interactions between host cells and bacteriophages.