Scientists Find Weak Spot Shared by Polio and Cold Viruses

Scientists just found the molecular playbook that viruses like polio and the common cold use to take over your cells, and it might lead to drugs that stop dozens of viruses in one shot.

Researchers at the University of Maryland, Baltimore County captured something never seen before: the exact moment when viral RNA recruits human and viral proteins to build its copying machine. The team, led by chemistry professor Deepak Koirala, spent years studying how enteroviruses—a family responsible for polio, encephalitis, myocarditis, and common colds—reproduce inside human cells.

The discovery centers on a cloverleaf-shaped structure in viral RNA that acts like a molecular switch. When a viral protein called 3CD attaches to this structure, the virus copies itself. When 3CD detaches, the RNA switches to making viral proteins instead.

"We previously determined the structure of the RNA alone, and other groups determined the structure of proteins, but now we've captured the structure of the RNA and proteins together," Koirala explains. Using advanced techniques like X-ray crystallography, the team watched these molecules interact in real time.

The researchers solved a longstanding mystery too. They proved that two complete 3CD proteins bind side by side on the viral RNA, settling a scientific debate about how the replication process actually begins.

The Bright Side

Here's where it gets really exciting: the team examined seven different enteroviruses and found nearly identical RNA cloverleaf structures across all of them. That similarity means the structure is critical to viral survival, making it an incredibly stable target for drug development.

Most antiviral drugs target one specific virus, which is why we need different medications for flu, HIV, and herpes. But because enteroviruses share this common weakness, scientists could potentially develop a single drug that works against the entire family—including viruses that currently have no treatment.

"Now we have another layer to test," Koirala says. "What if we target the RNA, or the RNA-protein interface, so that we break the interaction? Now that we have high-resolution structures, you can precisely design drug molecules to target them."

The research, published in Nature Communications, opens multiple pathways for drug development. Scientists were already creating drugs against the 3C and 3D proteins, but now they can also design medications that disrupt how these proteins bind to RNA in the first place.

Koirala marvels at what the research revealed about viral sophistication. Despite having genomes equivalent to just one human mRNA sequence, enteroviruses execute incredibly complex survival strategies inside our cells.

The breakthrough doesn't mean a universal antiviral will arrive tomorrow, but it provides the detailed molecular map drug designers need to start building one.