A new study says that a virus works by using the 'Swiss Army knife' protein on it tail, to cause infection.
Akio Kitao and colleagues focus on a group of viruses termed "bacteriophages," which literally means "bacteria eaters." These viruses infect bacteria like E. coli and usually make the bacteria dissolve.
Infection involves injecting their own DNA or RNA into the bacteria, so that the viral genetic material takes over control of the bacteria. The tools for doing so are among numerous invisible nanomachines - so small that 50,000 would fit across the width of a human hair - that work unnoticed in organisms ranging from microbes to people.
The scientists recreated intricate details of the protein's work as it helps the tail of the virus infect E. coli bacteria.
Their computer models show that the protein performs tasks in a regular sequence, starting with a screw-like motion as it begins to penetrate the outer membrane of E. coli.
The protein acts as a cell-puncturing bit, a pipe to draw away membrane debris and a tool to enlarge the puncture hole, among other functions.
The infection process demonstrates "a case where a single-function protein acquired multiple chemical functions" as different parts of its structure come in contact with bacterial membrane proteins.
The study has been published in the Journal of the American Chemical Society.