Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

A computer illustration of pink Zika virus particles

Zika virus (artist’s impression), which can cause birth defects in the babies of women infected during pregnancy, ties its RNA in protective knots. Credit: Maurizio De Angelis/Science Photo Library

Molecular biology

Tied in knots: Zika virus tangles are the most stable RNA known

A dangerous virus uses a ring-shaped structure to make its RNA resistant to attack.

Some viruses tie their RNA into intricate knots to prevent hostile cells from digesting it. Experiments now show that the Zika virus’s knotted RNA is the most stable RNA ever observed, paving the way to understanding how the virus eludes cellular defences.

To study the knot’s mechanics, Meng Zhao and Michael Woodside at the University of Alberta in Canada used optical tweezers, which rely on a laser beam to hold and move microscopic objects. The authors applied force to both of the RNA strand’s free ends, allowing them to repeatedly unfold and refold the knot and observe the steps involved in its formation. This revealed that a ring-shaped structure blocks the cell’s enzymes from digesting the RNA and generates the knot’s unusual mechanical stability.

By working out the steps required to form the ring, the researchers offer potential targets for future therapeutics to prevent the RNA from knotting. Many members of the flavivirus family — which includes the Zika, West Nile, dengue and yellow fever viruses — contain RNA with knots, and the authors hope their findings will contribute to disarming these viruses.

More Research Highlights...

Selected materials found in the gut contents of Tollund Man

The intestinal contents of a man killed in a prehistoric ritual (clockwise from upper left): barley, charred food that had been encrusted in a clay pot, flax seeds and sand. Credit: Peter Steen Henriksen, the Danish National Museum


The guts of a ‘bog body’ reveal sacrificed man’s final meal

Tollund Man, who lived more than 2,000 years ago, ate well before he was hanged.
Illustration of Earth with white lines showing the magnetic field.

Earth’s magnetic field (depicted as white lines in this artist’s impression) can be studied with observations from a constellation of commercial satellites. Credit: Mikkel Juul Jensen/Science Photo Library


Telecoms satellites’ new purpose: spying on Earth’s magnetic field

Clues to the forces generated by the planet’s core emerge from observations intended for satellite navigation.
Ageing of an artwork with graphene

After 130 hours of artificial ageing by visible light, the painting Triton and Nereid has lost some of the purple tint to the figures’ right, but a graphene film kept the bright pink at upper left undimmed. Credit: M. Kotsidi et al./Nature Nanotechnol.

Materials science

A graphene cloak keeps artworks’ colours ageless

A layer of carbon atoms preserves a painting’s vibrant hues — and can be applied and removed without damage.
Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing


Quick links