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 A new molecular player involved in T cell activation
07.12.2018 | Tokyo Institute of Technology

nachricht News About a Plant Hormone
07.12.2018 | Julius-Maximilians-Universität Würzburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

Im Focus: Three components on one chip

Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.

Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...

Im Focus: Substitute for rare earth metal oxides

New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals

Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.

Im Focus: A bit of a stretch... material that thickens as it's pulled

Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.

Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...

Im Focus: The force of the vacuum

Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications.

The vacuum is not empty. It may sound like magic to laypeople but it has occupied physicists since the birth of quantum mechanics.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

Expert Panel on the Future of HPC in Engineering

03.12.2018 | Event News

Inaugural "Virtual World Tour" scheduled for december

28.11.2018 | Event News

 
Latest News

A new molecular player involved in T cell activation

07.12.2018 | Life Sciences

High-temperature electronics? That's hot

07.12.2018 | Materials Sciences

Supercomputers without waste heat

07.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>