The Bacteriophage T7 Virion Undergoes Extensive Structural Remodeling During Infection

Phage Invasion Bacteriophages are responsible for much of bacterial evolution, both by imposing selection for resistance to infection and by horizontal gene transfer of host genes to new bacteria. However, we know surprisingly little about the initiation of phage infection.Huet al. (p.576 , published online 10 January) used high-throughput cryo-electron tomography and sub-volume analysis to examineEscherichia coli minicells infected with both wild-type and mutant T7 bacteriophages. High-resolution views of phage structures at different stages of infection reveal the de novo formation of an extended tail by the ejection of internal head proteins, in order to form the channel for DNA transport into the cytoplasm.