Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cellular Switches: From the RNA World to the “Modern” Protein World

07.02.2012
Heidelberg scientists discover the molecular mechanism of a G protein family

G proteins play a central role in cellular signal processing. They are described as molecular switches that oscillate between ‘on’ and ‘off’, regulated by effectors. Biochemists at Heidelberg University have now gained fundamental insights into the mechanics of these switches.

By studying the flagella, the organelles of locomotion in bacteria, researchers were able to identify an effector that turns a specific G protein ‘off’. They succeeded in visualising this process through X-ray crystallography. Their research results also provide insight into the evolution from the world of RNA to the “modern” world of proteins.

Bacteria need to be mobile to react to environmental changes, and in the case of pathogens, to reach the site of infection. Flagella are the organelles of locomotion in bacteria and the tiniest motors in the biosphere. When cells divide, the exact position of the new flagellum needs to be determined each time. The G protein FlhF is responsible for that task. FlhF is a molecular switch that apparently needed no effectors. “In our study, however, we identified a protein that assumes the effector role and were able to describe its mode of action, thereby fundamentally altering this previously held view”, explains Prof. Dr. Irmgard Sinning of the Heidelberg University Biochemistry Center.

The G protein FlhF, together with a signal sequence binding protein (SRP54) and its receptor (FtsY), constitutes the ancient family of SRP-GTPases, which consists solely of these three proteins and is responsible for the transport of proteins in or through a biological membrane. In all known organisms, SRP54 and FtsY regulate the transport of proteins using the signal recognition particle (SRP). Although the SRP system is already well understood, it was recently demonstrated that the protein SRP54 and the receptor FtsY interact with the SRP RNA in a way reminiscent of FlhF and its newly discovered effector.

“Our study of the G protein FlhF not only offers an explanation for the FlhF effector complex, it also integrates this knowledge into a general concept of SRP-GTPase activation through RNA or proteins”, says Dr. Gert Bange of the Heidelberg University Biochemistry Center. “We used FlhF to demonstrate how the ‘modern’ protein world replaced the original RNA world by means of a strikingly simple modification.” The results of the research were published in “Nature Structural & Molecular Biology”.

Original publication:
G. Bange, N. Kümmerer, P. Grudnik, R. Lindner, G. Petzold, D. Kressler, E. Hurt, K. Wild, I. Sinning:
Structural basis for the molecular evolution of SRP-GTPase activation by protein. Nat Struct Mol Biol. 2011, 18(12):1376-80. doi: 10.1038/nsmb.2141

Contact:
Prof. Dr. Irmgard Sinning / Dr. Gert Bange
Heidelberg University Biochemistry Center
phone: +49 6221 54-4780
irmi.sinning@bzh.uni-heidelberg.de
gert.bange@bzh.uni-heidelberg.de

Communications and Marketing
Press Office
phone: +49 6221 542311
presse@rektorat.uni-heidelberg.de

Marietta Fuhrmann-Koch | idw
Further information:
http://www.uni-heidelberg.de

More articles from Life Sciences:

nachricht Flavins keep a handy helper in their pocket
25.04.2018 | University of Freiburg

nachricht Complete skin regeneration system of fish unraveled
24.04.2018 | Tokyo Institute of Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Getting electrons to move in a semiconductor

25.04.2018 | Physics and Astronomy

Reconstructing what makes us tick

25.04.2018 | Physics and Astronomy

Cheap 3-D printer can produce self-folding materials

25.04.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>