title: Visualization of bacteriophage P1 infection by cryo-electron tomography of tiny Escherichia coli.
abstract: Bacteriophage P1 has a contractile tail that targets the conserved lipopolysaccharide on the outer membrane surface of the host for initial adsorption. The mechanism by which P1 DNA enters the host cell is not well understood, mainly because the transient molecular interactions between bacteriophage and bacteria have been difficult to study by conventional approaches. Here, we engineered tiny E. coli host cells so that the initial stages of P1-host interactions could be captured in unprecedented detail by cryo-electron tomography. Analysis of three-dimensional reconstructions of frozen-hydrated specimens revealed three predominant configurations: an extended tail stage with DNA present in the phage head, a contracted tail stage with DNA, and a contracted tail stage without DNA. Comparative analysis of various conformations indicated that there is uniform penetration of the inner tail tube into the E. coli periplasm and a significant movement of the baseplate away from the outer membrane during tail contraction.
authors: Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Houston, TX 77030, USA. Jun.Liu.1@uth.tmc.edu
authors: Jun
authors: J
authors: Liu
authors: Cheng-Yen
authors: CY
authors: Chen
authors: Daisuke
authors: D
authors: Shiomi
authors: Hironori
authors: H
authors: Niki
authors: William
authors: W
authors: Margolin
mesh_terms: D017101:Bacteriophage P1 / Q000502:physiology* / Q000648:ultrastructure; D020285:Cryoelectron Microscopy; D055032:Electron Microscope Tomography; D004926:Escherichia coli / Q000166:cytology* / Q000648:ultrastructure / Q000821:virology*; D021621:Imaging, Three-Dimensional; D053586:Virus Internalization