Scientists Catch Virus in the Act of Infecting a Cell

Posted on January 12, 2013

T7 Phage


Researchers from The University of Texas at Austin and The University of Texas Health Science Center at Houston (UT Health) Medical School announced that they have caught a virus (called T7) in the act of infecting a cell. Researchers observed the changes in the structure of a virus as it infects an E. coli bacterium. The research paper was published in Science Epxress.

The researchers found that the T7 virus has six tail fibers folded back against its capsid. The virus can extend these fibers to "walk" across its host cell surface to find a site to infect. The researchers say the virus behaves "a bit like a planetary rover."

Ian Molineux, professor of biology at The University of Texas at Austin, said in a release that the idea that phages "walk" over the cell surface was previously proposed, but their paper provides the first experimental evidence. This is also the first time scientists have made images showing how the virus's tail extends into the host, which allows it to infect a cell with its DNA.

Molineux says, "Although many of these details are specific to T7, the overall process completely changes our understanding of how a virus infects a cell."

An animation was created that shows the T7 virus "walking" across a cell to find the best place to infect the cell. Take a look:



Image: From Hu et. al. 2013. Science Express