December 30, 2008: Peering at structures only atoms across, researchers have identified the clockwork that drives a powerful virus nanomotor.

Because of the motor’s strength — to scale, twice that of an automobile — the new findings could inspire engineers designing sophisticated nanomachines. In addition, because a number of virus types may possess a similar motor, including the virus that causes herpes, the results may also assist pharmaceutical companies developing methods to sabotage virus machinery.

Researchers from Purdue University in West Lafayette, Ind., and the Catholic University of America in Washington, D.C., collaborated on the study that appears in the Dec. 26, 2008, issue of the journal Cell.

“The discovery of how this virus motor functions represents a significant milestone in the investigation of viral processes,” says David Rockcliffe, the program director who oversees a National Science Foundation (NSF) grant that partly funded the research. “This research is a breakthrough that not only may lead to the development of a means of arresting harmful infections, but it also points to possible ways in which nano-devices could be fashioned.”

The virus in the study, called T4, is not a common scourge of people, but its host is: the bacterium Escherichia coli (E. coli). Purdue researchers studied the virus structures, such as the motor, while the Catholic University researchers isolated the virus components and performed biochemical analyses.

“T4 is what’s called a ‘tailed virus’,” says Purdue biologist Michael Rossmann, one of the lead researchers for the study. “It is actually one of the most common types of organisms in the oceans of the world. There are many different, tailed, bacteria viruses–or phages–and all of these phages have such a motor for packaging their DNA, their genome, into their pre-formed heads.”

For the recent study, analyses involved two sophisticated instruments capable of studying structures at the nanometer scale. One of the techniques, x-ray crystallography, showed the ordered arrays of atoms in the various structures, while another, called cryo-electron microscopy, let the researchers study the broader shape of the structures without the need for coating or drying out the specimens.

While many questions remain, adds Rossmann, the virus may lend itself to a variety for medical purposes. One example Rossmann cites is as a potential new weapon to fight dangerous microbes.

“Bacteriophages like T4 are a completely alternative way of dealing with unwanted bacteria. The virus can kill bacteria in its process of reproduction, so use of such viruses as antibiotics has been a long looked-for alternative to overcome the problems which we now have with antibiotics.”