SARS-CoV-2

What the structure of the coronavirus can tell us

Researchers hope that a new visualization of the architecture of SARS-CoV-2 will show them how to defeat it.

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Like any virus, the novel coronavirus is a germ that tries to burrow into a cell and turn it into a virus-replicating factory. If it succeeds, it can produce an infection — in this case, a respiratory disease. The type of cells a virus targets and how it enters them depend on how the virus is built.

This virus gets its family name from a telltale series of spikes — tens or even hundreds of them — that circle its bloblike core like a crown, or corona. Virologists know from studying its close cousins, viruses that cause SARS and MERS, that the spikes interact with receptors on cells like keys in locks, enabling the virus to enter.

Spikes covering the virus form the corona.

Spikes covering the virus

form the corona.

Spikes covering the virus

form the corona.

Very recent innovations in imaging techniques enabled researchers to peer so closely at the novel virus’s spikes that they created a model of one, right down to the atoms, and are beginning to reveal its secrets.

It has a clever disguise.

Sugars dot the outside of the spike, just like sugars dot the outside of regular human cells, said David Veesler, a structural virologist at the University of Washington who led a team that visualized the SARS-CoV-2 spike and published a March 19 paper on its architecture.

This carbohydrate camouflage makes the virus more difficult for the human immune system to recognize.

Model of a spike

The sugars on the spike act as camouflage

Model of a spike

The sugars on the spike act as camouflage.

Model of a spike

The sugars on the spike act as camouflage.

It seems to attach by opening and closing.

Each spike is made of three identical proteins twisted together, Veesler said.

His team captured images of the ends of these proteins opening in the spike’s cap-like apex before and during the attempt to bind to a receptor. Studies on SARS- and MERS-causing viruses indicate that all three proteins in a spike have to open for it to gain access to a cell.

A vaccine may be able to exploit the openings.

Proteins

Apex

Stem

A vaccine may be able to exploit the openings.

Proteins

Apex

Stem

A vaccine may be able

to exploit the openings.

Proteins

Apex

Stem

Experts say a vaccine is at least a year away, but they’re coming up with strategies now.

One may be able to trigger antibodies that strike areas of the protein that are exposed when it opens, said virologist Vineet Menachery, who specializes in the study of coronaviruses at the University of Texas Medical Branch in Galveston.

The holy grail of vaccines, Veesler said, would trigger antibodies that attack a spike’s stem, which is so similar to other coronaviruses that a single vaccine might protect against several strains instead of just one.

One treatment avenue may be to block receptors so the spikes have nowhere to attach.

Perhaps a concert of strategies could work together against these tiny invaders, each 1,000 times smaller than the cells they infect. After all, the natural human immune response plays defense in many ways at once.

While we wait for a vaccine, we have ways to defeat it.

Soap — bar soap, liquid soap, laundry detergent and such — is virus kryptonite, which is why the message “Wash your hands!” is everywhere. But Menachery said heat and ultraviolet light are two other ways to neutralize a coronavirus, and each of these methods works in a different way.

Soap and water break the virus membrane.

RNA

Ultraviolet light disrupts the genetic material.

UV light

Heat breaks the structure of the spike.

Soap and water break the virus membrane.

RNA

Ultraviolet light disrupts the genetic material.

UV light

Heat breaks the structure of the spike.

Soap and water break the virus membrane.

Ultraviolet light disrupts the genetic material.

Heat breaks the structure of the spike.

UV light

RNA

Heat breaks the structure of the spike.

Soap and water break the virus membrane.

Ultraviolet light disrupts the genetic material.

UV light

RNA

Soap and water break the virus membrane.

Ultraviolet light disrupts the genetic material.

Heat breaks the structure of the spike.

UV light

RNA

After about 20 seconds of contact, soap breaks apart the fragile, fatty membrane that holds the virus together. Disinfecting agents with at least 60 percent alcohol puncture and destroy the virus in a similar way.

Extreme heat — near boiling — causes the proteins in the spikes to unravel and lose their shape, deactivating them. (A human fever is not hot enough to do this; it’s unclear what effect warm summer weather will have.)

And ultraviolet light has been used as a disinfectant for a century in hospitals and water supplies. It shatters the genetic material inside viruses, bacteria and other microbes. However, it doesn’t always work uniformly, Menachery said, and disinfecting UV light can’t be used with people around because it damages human cells.

Bonnie Berkowitz

Bonnie Berkowitz is a reporter in the Graphics department at The Washington Post who often focuses on Health & Science topics.

Aaron Steckelberg

Aaron Steckelberg is a senior graphics editor who creates maps, charts and diagrams that provide greater depth and context to stories over a wide range of topics. He has worked at the Post since 2016.

John Muyskens

John Muyskens is a graphics editor at the Washington Post specializing in data reporting.

About this story

SARS-CoV-2 spike protein model provided by David Veesler, assistant professor at the University of Washington department of biochemistry.

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