Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Biologists probe the machinery of cellular protein factories

15.09.2006
Proteins of all sizes and shapes do most of the work in living cells, and the DNA sequences in genes spell out the instructions for making those proteins. The crucial job of reading the genetic instructions and synthesizing the specified proteins is carried out by ribosomes, tiny protein factories humming away inside the cells of all living things.

Harry Noller, the Sinsheimer Professor of Molecular Biology at the University of California, Santa Cruz, has been studying the ribosome for more than 30 years. His main goal is to understand how the ribosome works and how it evolved, but there are also practical reasons to pursue this research. Many of the most effective antibiotics work by targeting bacterial ribosomes, and findings by Noller and others have led to the development of novel antibiotics that hold promise for use against germs that have developed resistance to current drugs. Drug-resistant staph infections, for example, are a serious problem in hospitals.

Noller's laboratory achieved breakthroughs in 1999 and 2001, producing the first high-resolution images of the molecular structure of a complete ribosome. Now, his team has made another major advance with an even higher-resolution image that enables them to construct an atom-by-atom model of the ribosome.

The new picture shows details never seen before and suggests how certain parts of the ribosome move during protein synthesis. A paper describing the new findings will be published in the September 22 issue of the journal Cell and is currently available online.

... more about:
»Messenger »Noller »RNA »amino acid »ribosome

"We can now explain a lot of the results from biochemical and genetic studies carried out over the past several decades," Noller said. "This structure gives us another frame in the movie that will eventually show us the whole process of the ribosome in action."

The ribosome is a complex molecular machine made up of proteins and RNA molecules. The bacterial ribosomes studied in Noller's lab (obtained from the bacterium Thermus thermophilus) are made up of three different RNA molecules and more than 50 different proteins.

Noller proposed in the early 1970s that the RNA component was responsible for carrying out the ribosome's key functions. At the time it was considered a "crackpot idea," but subsequent findings by Noller and others proved he was right.

"It was a completely heterodox view when we first proposed it, but it is now the accepted paradigm," said Noller, who directs the Center for Molecular Biology of RNA at UCSC. "Our latest results confirm that the ribosomal RNA is really the key to ribosome function. The proteins are also involved, but more peripherally," he said.

To make a new protein, the genetic instructions are first copied from the DNA sequence of the gene into a messenger RNA molecule. The ribosome then reads the genetic code from the messenger RNA and translates it into the structure of a protein.

Proteins are linear molecules that fold into complex three-dimensional shapes to carry out their functions. They are made from amino acid building blocks, and the sequence of amino acids determines the protein's structure. Amino acids are carried to the ribosome by transfer RNA molecules. On the ribosome, the transfer RNAs recognize specific sequences of genetic code on the messenger RNA, and the amino acids are then joined together in the proper order.

The images from Noller's group not only show the complete ribosome, they show it with a messenger RNA and two full-length transfer RNAs bound to it. "We can now see the details of most of the interactions between the ribosome, the messenger RNA, and the transfer RNAs," Noller said.

The results provide a snapshot of the molecular machine in action. By comparing his images with those obtained by other groups that have caught the ribosome or its subunits in different positions, Noller is finding clues to the molecular motions with which the ribosome does its work.

"Our next goal is to trap the ribosome in other functional states to get more frames of the movie," he said.

The authors of the paper, in addition to Noller, are postdoctoral researcher Andrei Korostelev, senior scientist Sergei Trakhanov, and postdoctoral researcher Martin Laurberg. The researchers used a technique called x-ray crystallography, which involves growing crystals of purified ribosomes, shining a focused beam of x-rays through the crystals, and analyzing the resulting diffraction pattern. Trakhanov prepared the crystals and Korostelev and Laurberg performed the crystallography and solved the structure, Noller said.

Tim Stephens | EurekAlert!
Further information:
http://www.ucsc.edu

Further reports about: Messenger Noller RNA amino acid ribosome

More articles from Life Sciences:

nachricht Scientists coax proteins to form synthetic structures with method that mimics nature
15.01.2019 | University of Texas at Austin

nachricht DNA library of apoid wasps published
15.01.2019 | Staatliche Naturwissenschaftliche Sammlungen Bayerns

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nanocellulose for novel implants: Ears from the 3D-printer

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

Im Focus: Mission completed – EU partners successfully test new technologies for space robots in Morocco

Just in time for Christmas, a Mars-analogue mission in Morocco, coordinated by the Robotics Innovation Center of the German Research Center for Artificial Intelligence (DFKI) as part of the SRC project FACILITATORS, has been successfully completed. SRC, the Strategic Research Cluster on Space Robotics Technologies, is a program of the European Union to support research and development in space technologies. From mid-November to mid-December 2018, a team of more than 30 scientists from 11 countries tested technologies for future exploration of Mars and Moon in the desert of the Maghreb state.

Close to the border with Algeria, the Erfoud region in Morocco – known to tourists for its impressive sand dunes – offered ideal conditions for the four-week...

Im Focus: Programming light on a chip

Research opens doors in photonic quantum information processing, optical signal processing and microwave photonics

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new integrated photonics platform that can...

Im Focus: Physicists uncover new competing state of matter in superconducting material

A team of experimentalists at the U.S. Department of Energy's Ames Laboratory and theoreticians at University of Alabama Birmingham discovered a remarkably long-lived new state of matter in an iron pnictide superconductor, which reveals a laser-induced formation of collective behaviors that compete with superconductivity.

"Superconductivity is a strange state of matter, in which the pairing of electrons makes them move faster," said Jigang Wang, Ames Laboratory physicist and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

11th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Aachen, 3-4 April 2019

14.01.2019 | Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

 
Latest News

Scientists coax proteins to form synthetic structures with method that mimics nature

15.01.2019 | Life Sciences

Next generation photonic memory devices are light-written, ultrafast and energy efficient

15.01.2019 | Information Technology

Viennese scientists develop promising new type of polymers

15.01.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>