Choreographed origami: Folding ribosomal RNA requires paired tagging sequence

Oct 14, 2013
Structure of the RNA-tagging machinery shows that only one pair of proteins (blue) can add tags to the RNA (red) at a time. Credit: EMBL/Carlomagno

the cell's protein factories – is like a strictly choreographed dance, scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, have discovered. To build these factories, other 'machines' inside the cell have to produce specific RNA molecules and fold them into the right shape, then combine the folded RNA with proteins to form a working ribosome. Like a budding origami artist pencilling in the folds, the cell uses tags called methyl groups to help mark where and how an RNA molecule should be folded.

In work published online today in Nature, the scientists have discovered that pairs of these tags are added in a specific order. The study combined at EMBL and neutron scattering at the Institut Laue-Langevin (ILL) in Grenoble, France.

Led by Teresa Carlomagno at EMBL, the scientists were able to determine the 3D structure of the complex that adds methyl tags to the RNA, with the RNA molecules attached. They discovered that the different components of this tagging machine pair up and move in sequence, like dancers following a set choreography.

"We found that the complex has four copies of each protein, and four methylation sites on the RNA, but those methylation sites aren't all the same," Carlomagno says. "They come in pairs, and one pair has to be methylated before the other."

The fact that the pairs of tags have to be added in a particular order could be a way for the cell to control how the RNA is folded, and ultimately when and where ribosomes are formed, the scientists believe.

Explore further: Feeding RNAs to a molecular shredder: Scientists unravel the structure of a regulatory protein complex in RNA disposal

More information: The structure of the box C/D enzyme reveals regulation of RNA methylation, Nature, DOI: 10.1038/nature12581

Related Stories

Genes protect themselves against being silenced

Oct 10, 2013

Harvard Stem Cell Institute (HSCI) researchers have settled a century-old debate over whether occurrence of DNA methylation acts to silence gene expression, or if genes are turned off by other means before ...

Recommended for you

Cell division speed influences gene architecture

13 hours ago

Speed-reading is a technique used to read quickly. It involves visual searching for clues to meaning and skipping non-essential words and/ or sentences. Similarly to humans, biological systems are sometimes ...

Secret life of cells revealed with new technique

15 hours ago

(Phys.org) —A new technique that allows researchers to conduct experiments more rapidly and accurately is giving insights into the workings of proteins important in heart and muscle diseases.

In the 'slime jungle' height matters

16 hours ago

(Phys.org) —In communities of microbes, akin to 'slime jungles', cells evolve not just to grow faster than their rivals but also to push themselves to the surface of colonies where they gain the best access ...

Queuing theory helps physicist understand protein recycling

Apr 22, 2014

We've all waited in line and most of us have gotten stuck in a check-out line longer than we would like. For Will Mather, assistant professor of physics and an instructor with the College of Science's Integrated Science Curriculum, ...

User comments : 0

More news stories