Video: Animation of Tiny One Nanometer Weapon Viruses Use to Kill Bacteria

Posted on April 11, 2012

EPFL scientists have measured tiny one nanometer weapons viruses use to attack and kill bacteria. The single nanometer weapon is roughly 20 times the diameter of a helium atom. φ92, a family of bacteriophage viruses, uses this weapon to attack salmonella and coliform bacteria. This discovery was published here in Structure.

Seyet LLC, Petr Leiman (EPFL) and Michael Rossmann (Purdue University) created a video to show a T4 bacteriophage attacking a bacteria. The body of a phage is made up of two main parts. The first part is a hollow head called a capsid, which contains the genetic material. The second part consists of a tube, a group of appendages resembling feet, and a device designed to penetrate the membrane of its host - the needle-like tip is at the furthest extremity of the virus. The weapon itself is made up of three chains of identical proteins. The intertwined molecules form an appendage sharp enough to penetrate the bacterial membrane.

Phages recognize sugars and proteins on the surface of their preferred host bacteria. The virus attaches its feet to the victim and a chain of proteins uncoils, pushing the injection tube and its tip through the victim's membrane like a hypodermic needle. The tip then detaches from the tube and, like an uncorked bottle of champagne, the pressurized genetic material in the capsid is injected into the bacterium. The phage then begins to reproduce inside its victim.

Take a look: