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Zika Virus Structure
New microscopy images of the Zika virus reveal a bumpy, golf ball‒shaped structure, similar to that of the dengue and West Nile viruses, researchers report March 31 in Science. It's the first time scientists have gotten a good look at Zika, the infamous virus that has invaded the Americas and stoked fears that it is causing birth defects and a rare autoimmune disease.

The research team that determined it's structure used a technique called cryoelectron microscopy to create a three-dimensional picture of Zika. It's a pretty sharp image and scientists can clearly see the virus' shape and can even make out sugars protruding from its surface.
These sugars, which look like little red doorknobs, hang from proteins in Zika's shell. The knobs may help Zika attach to - and infect - human cells. The team discovered that Zika's knobby regions look slightly different from those of related viruses. Zika's sugar-decorated proteins "fold a little differently," Sirohi says. And that might let Zika make different contacts with attachment sites on cells, called receptors. That could "influence what kind of cell the virus infects," she says. These differences could explain why Zika infects cells not typically targeted by dengue or West Nile.
One of the receptors targeted by Zika could be AXL, a protein crowded on the surface of neural stem cells, researchers propose March 30 in a separate study published online in Cell Stem Cell. Zika virus is thought to preferentially infect these early-development brain cells, and it could potentially use AXL as an easy entry point, study coauthor Arnold Kriegstein of the University of California, San Francisco and colleagues suggest.
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