Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Erratic proteins: new insights into a transport mechanism

30.09.2013
The outer membrane of bacteria contains many proteins that form tiny pores. They are important for absorbing nutrients and transmitting signals into the cell.

The research group of Sebastian Hiller, Professor of Structural Biology at the Biozentrum, University of Basel, has now shown for the first time at atomic resolution, that these pore proteins are transported in an unstructured, constantly changing state to the outer bacterial membrane. This landmark study was recently published in the scientific journal “Nature Structural and Molecular Biology”.

The cell membrane of a bacterium is a natural barrier to the environment and at the same time, their door to the world. Gram-negative bacteria surround themselves with two membrane layers. They communicate with the environment through proteins that form tiny pores in the outer cell membrane. How these membrane proteins reach their target destination in the bacterium Escherichia coli could now be observed for the first time at the atomic level by Professor Sebastian Hiller, from the Biozentrum at the University of Basel.

Molecular “ferry” ensures safe protein transport
New proteins are produced in the protein factories inside the cell. Proteins destined for the outer membrane require a molecular “ferry” to remain intact as they pass the aqueous layer between the two membranes. The protein Skp is such a ferry, transporting the not yet folded proteins across the periplasmic space. At the outer membrane, they fold into their three-dimensional structure and incorporate into the outer membrane.

The current study by Hiller provides an exceptional and deep insight into this transport mechanism. The membrane protein is loosely embedded in the solid structure of Skp during transport and does not adopt on a defined spatial structure itself. “Amazingly, the unfolded protein changes its state constantly – faster than thousand times per second and more than ten million times during the crossing,” explained Hiller. “Only through employing modern nuclear magnetic resonance spectroscopy, it has become possible to detect this dynamic behavior within Skp.” Transporting the membrane protein in such a changing state does not require energy and allows for its rapid release at the destination.

Dynamic transport as a general principle
Although the structure of Skp has been known for a long time, the current study shows that the dynamics of the Skp-membrane protein complex is important for the formation of the outer membrane proteins. With the atomic resolution measurements, Hiller and his team were also able to uncover a general principle how proteins can be transported without requiring energy. In the future, the team of scientists wants to investigate further proteins that are involved in the transport and folding process.
Original Source
Björn M Burmann, Congwei Wang & Sebastian Hiller (2013)
Conformation and dynamics of the periplasmic membrane-protein–chaperone complexes OmpX–Skp and tOmpA–Skp

Nature Structural & Molecular Biology, Published online 29 September 2013 | doi: 10.1038/nsmb.2677

Reto Caluori | idw
Further information:
http://www.unibas.ch
http://www.unibas.ch/index.cfm?uuid=96855398D62121F8339989EA09D23513&type=search&show_long=1&o_lang_id=2

More articles from Life Sciences:

nachricht New catalyst controls activation of a carbon-hydrogen bond
21.11.2017 | Emory Health Sciences

nachricht The main switch
21.11.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Previous evidence of water on mars now identified as grainflows

21.11.2017 | Physics and Astronomy

NASA's James Webb Space Telescope completes final cryogenic testing

21.11.2017 | Physics and Astronomy

New catalyst controls activation of a carbon-hydrogen bond

21.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>