Transmission Electron Microscopy Studies of Cellular Responses to Entry of Virions: One Kind of Natural Nanobiomaterial
Figure 3
Observation of bacteriophage-host interaction with cryoelectron microscopy. (a) Cryo-electron tomography of podovirus P-SSP7 infecting Prochlorococcus. An infecting phage subtomograms with the portal vertex oriented to the cell surface. The phage tail fibers are extended horizontally (red arrow marked) [24]. (b) Conformational changes of phage P1 during tail contraction and DNA injection. The E.coli marked is only part of the cell, DNA marked pink stays in the capsid, and the tail is not contracted (left). Structure of the contracted phages has no DNA (right) [26]. (c) Electron micrograph of the virulent lactococcal phage p2. Overall structure of phage p2 (right) showing the capsid (blue, top), the tail, formed of rings of the major tail protein hexamers (gold), the globular baseplate (gold, bottom) (insert). The baseplate is reconstructed by single particles analysis. The receptor-binding protein (RBP) positions are identified by blue arrows or a blue dot. The RBP head is pointing upwards [29].
