In new research, scientists at the University of Michigan and Howard Hughes Medical Institute have discovered how a protein chaperone called HdeA, which helps protect bacteria like the notorious Escherichia coli from the ravages of stomach acid, saves energy while keeping proteins from forming destructive clumps.
The research is described in a paper published online this week in the Proceedings of the National Academy of Sciences.
Proteins in disease-causing bacteria like E. coli unfold when they land in stomach acid after being accidentally ingested by humans and other animals. This unfolding stops the proteins from working and could spell doom for the bacteria if the chaperone HdeA didn't step in. HdeA works by binding very tightly to the unfolded proteins while the bacteria are in the stomach. By attaching to the bacterial proteins, the chaperone stops them from tangling like slow-dancing teens, which could kill the bacteria.
The researchers discovered how HdeA is then able to let go of the unfolded proteins as the bacteria pass into the small intestine so that the proteins refold instead of clumping together.
"HdeA uses a unique timed-release mechanism," said postdoctoral fellow Tim Tapley, who spearheaded the work. "If the proteins were released all at once they would likely clump together, killing the bacteria. What we found instead is that the chaperone HdeA lets go of them gradually, making it more likely that they fold back up into their proper form than clump together."
While most molecular chaperones consume large amounts of cellular energy in order to function, HdeA instead taps energy freely available in its living environment.
"In this way, HdeA is a bit like a wind powered machine, except that instead of harnessing wind, HdeA uses the energy from pH changes in the surrounding environment as the bacteria move from the acid stomach to the slightly alkaline small intestine," said James Bardwell, in whose lab the work was done. Bardwell is a professor of molecular, cellular and developmental biology and of biological chemistry, as well as a Howard Hughes Medical Institute Investigator.
Tapley and Bardwell were assisted by research specialist Sumita Chakraborty, associate professor Ursula Jakob and Titus Franzmann, a postdoctoral fellow in the lab of Stefan Walter. The research was funded in part by the Howard Hughes Medical Institute and the National Institutes of Health.
James Bardwell: http://www.ns.umich.edu/htdocs/public/experts/ExpDisplay.php?ExpID=1016
Proceedings of the National Academy of Science: http://www.pnas.org/
Bacteria as pacemaker for the intestine
22.11.2017 | Christian-Albrechts-Universität zu Kiel
Researchers identify how bacterium survives in oxygen-poor environments
22.11.2017 | Columbia University
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....
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...
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...
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....
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,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
22.11.2017 | Business and Finance
22.11.2017 | Physics and Astronomy
22.11.2017 | Physics and Astronomy