Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genomics reveals mechanism of heat resistance in bacteria

23.08.2005


Thermophilic bacteria can thrive in extreme heat because their proteins have an abundance of disulfides (yellow, above), covalent bonds between sulfur atoms that improve stability and likely boost heat-tolerance. (Yeates et al.)


Warm-blooded creatures maintain a relatively stable body temperature that cannot tolerate the stress of intense heat (or cold). When it’s too hot proteins destabilize and degrade--in some cases, with fatal results. But some bacterial and archaeal organisms appear to defy nature (as we think of it) by flourishing in extremely high temperatures. The archaeal microbe Pyrobaculum aerophilum, for example--originally found in a boiling marine water hole in Italy--thrives at ~100 °C (212 °F).

Published online this week in the open-access journal PLoS Biology Todd Yeates and colleagues from UCLA have investigated the mechanisms that engineer this remarkable heat resistance. By way of an elegant analysis of publicly available genome sequence and protein structure data, they answer the question: how do these thermophilic bacteria and archaea manage to maintain active, stable proteins at such high temperatures? The authors found that proteins from P. aerophilum along with some other thermophiles have many disulfide bonds (covalent bonds between two spatially proximate cysteines), which are known to improve stability.

By mapping intracellular gene sequences from 199 prokaryote genomes onto sequence-related proteins with known three-dimensional structures, they produced structural models which revealed when disulfide bonds are likely to form. A bias was found for disulfides in a set of thermophilic genomes. To prove that these predictions really do form disulfide bonds, the authors solved the structure of one protein from P. aerophilum--which was indeed stabilized by three disulfide bonds.



Disulfide bonds are more commonly formed outside or between cells in multicellular organisms. The high numbers of bonds observed in these prokaryotes challenge our ideas of how disulfide bonds form. Given the difficulty for disulfides to form in such organisms, the authors investigated which proteins are present in the disulfide-rich organisms as compared with the proteins in other organisms (also known as phylogenetic profiling). They found a protein called protein disulfide oxidoreductase (PDO) present in all of the disulfide-rich thermophiles which is not seen in the other prokaryotes. As its name suggests, this protein likely plays a key role in the formation of disulfides in these heat-tolerant bugs.

Yeates and colleagues have considerably advanced our understanding of how proteins withstand and function at high temperatures via stabilizing disulfide bonds in these thermophilic organisms. Yet, since this correlation of extra disulfides and the PDO is not common to all thermophiles, it is likely that this is not the only method employed in heat resistance. Probably several different mechanisms are employed to enable thermophiles to flourish in extreme conditions. As the authors show here, genome sequence and structure data can help us to uncover these mechanisms.

Paul Ocampo | EurekAlert!
Further information:
http://www.plosbiology.org
http://www.plos.org

More articles from Life Sciences:

nachricht Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology

nachricht Migrating Cells: Folds in the cell membrane supply material for necessary blebs
23.11.2017 | Westfälische Wilhelms-Universität Münster

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

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....

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

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>