A virus can behave like a predator during its search for the ideal host. A new animation shows how it finds and infects a cell. Here, a T7 virus, with its head colored blue and tail colored red, searches for a suitable E. coli bacterium. While what we're about to see is specific to T7, a similar process may allow other viruses to infect cells. The details may offer future targets for drug development. The T7 virus has six ultra-thin fibers, shown here in yellow, that are folded at the base of the head. While roaming the cell, the virus extends a few of these fibers. This action allows the virus to move freely around the cell. The fibers "walk" across the surface of an E. coli until the virus locates an optimal site for infection. As it prepares to infect, all of the virus's fibers bind to the outer membrane of the cell. The virus then undergoes a major structural change as it ejects some of its proteins, represented in green, through the bacterium's cell membrane. This creates a path for the virus's genetic material, shown in purple, to enter and subsequently infect the cell. After the viral DNA has been released, the protein path collapses and the cell's membrane reseals. Animation developed by Bo Hu and Jun Liu, UT Health, and published in Science. Read more.
Featured in the February 21, 2013, issue of Biomedical Beat.