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 When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short
23.03.2017 | Institut für Pflanzenbiochemie

nachricht WPI team grows heart tissue on spinach leaves
23.03.2017 | Worcester Polytechnic Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short

23.03.2017 | Life Sciences

Researchers use light to remotely control curvature of plastics

23.03.2017 | Power and Electrical Engineering

Sea ice extent sinks to record lows at both poles

23.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>