It's the smallest armor-piercing weapon in the biological universe.
That's how some have described the microscopic "needle" that a family of odd-looking viruses use to attack germs. And happily for humans, the germs that get the end of the short stick are salmonella and coliform bacteria--which can cause dangerous and potentially lethal illnesses in humans.
It's no secret that these so-called bacteriophage viruses latch onto bacteria and inject them with their genetic material--as seen in this video animation. But now researchers at Switzerland's Ecole Polytechnique Deferal De Lausanne have used X-ray crystallography to gain an unprecedented look at the appendage, according to a written statement released by the university. The researchers reported in the journal Structure that it is roughly 20 times the diameter of a helium atom.
And the tiny tip of the tiny appendage is studded with iron.
"We managed to determine not only the size, but the complete structure of the tip as well," Dr. Christopher Browning, a postdoctoral researcher at the university, said in the statement. "We still are not sure what it's used for, but to the extent that this element is toxic, we have very good reason to think that it's not there by accident."
Remarkable as it is, the appendage is no more remarkable than the rest of the bacteriophage--a tiny six-legged organism that looks something like a mechanical bug or perhaps the lunar module that took Apollo astronauts to the moon. Once a bacteriophage "lands" on a target bacterium, it uses the needle to pierce the germ's outer membrane and injects the hapless microbe with its own genetic material. Once inside, the bacteriophage's genes "hijack" the bacterium, turning it into a factory to make more bacteriophages.
Research into this tiny world could have big implications, according to the statement. Bacteriophages are considered promising tools in the fight against infectious bacteria--to supplement or even replace traditional antibiotic drugs.
