WEST LAFAYETTE, Ind. Like sleuths on the trail of a family of thieves, scientists have caught another viral intruder in action, revealing how two related viruses use similar but distinct strategies to enter cells.

A research group from Purdue University and State University of New York at Stony Brook has analyzed in molecular detail how the poliovirus interacts with a cell to gain entry. The group then compared the virus' tactics to those of human rhinoviruses, common cold viruses that are similar in size and structure to polioviruses. Both viruses belong to a family called picornaviruses.

Though these two sorts of viruses use different receptors to enter a cell, the scientists found that the receptors have a similar "footprint" and interact with the virus at similar sites on the virus shell, says Michael Rossmann, who is the Hanley Distinguished Professor of Biological Sciences at Purdue.

"Rhinoviruses and polioviruses each have shells that contain deep crevices or canyons, and this is the site at which binding occurs," Rossmann says. "In fact, this site may be a trigger for initiation of the subsequent uncoating step required for viral infection."

By comparing the processes used by rhinoviruses and polioviruses, scientists can for the first time describe in molecular detail the process by which a virus selectively attaches to its particular receptor. The findings also provide new insights on what differentiates one virus from another, and they may suggest ways for developing drugs that prevent illnesses caused by viral pathogens.

"Specificity is key to allowing the virus to enter a cell," Rossmann says. "A virus and its receptor must be perfect complements, like a lock and a key, in order for infection to occur."

Details of the study are in the Jan. 4 issue of the journal Proceedings of the National Academy of Sciences. Similar results were found by another team of researchers from the National Institutes of Healt
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Contact: Susan Gaidos
sgaidos@purdue.edu
765-494-2081
Purdue University
3-Jan-2000