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 Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>