Researchers have learned how the bacterial virus, bacteriophage T4, attacks its host, the E. coli bacterium. This discovery could eventually lead to a new class of antibiotics.
The research describes for the first time how the virus uses a needle-like, biochemical puncturing device to invade its host. "We show, in its entirety, a complex machine that allows a virus to efficiently infect its unfortunate host cell, the E. coli. The baseplate portion of the virus tail is essential in this process," says lead researcher Michael Rossmann of Purdue University, US.
Because of increasing resistance of infectious bacteria to pharmaceutical antibiotics like penicillin, new antibiotic tools are needed. Bacteriophages may play a future role in controlling disease-causing bacteria. "Knowing the exact mechanism of T4 bacteriophage infectivity is a significant breakthrough. This information could eventually help in creating "designer viruses" that could be the next class of antibiotics," said Kamal Shukla, the NSF project officer for this research.
Although only about a hundred nanometres in length and width, bacteriophage T4 is one of the largest of the bacterial viruses. It is also a tailed virus because it has a tail with fibres that are used to grip its host. The tailed viruses are very common; up to one billion phages can exist in a millilitre of freshwater.
"Our research described for the first time the structure of phage baseplate proteins and their role in cutting through the host cell wall," said Rossmann.
