The research is a collaboration between molecular biologists and physicists. ”The molecular biologists have knowledge of how the cell functions and of the interplay between the intercellular parts, while the physicists have the expertise and the technique to be able to measure and analyze the physical processes.” says Lene Oddershede, physicist at the Niels Bohr Institute, University of Copenhagen. This interdisciplinary work between physics and biology has been very fruitful and will be published April 3rd in the prestigious scientific journal PNAS, Proceedings of the National Academy of Sciences.
The researchers have investigated how a virus exploits the machinery of human cells to produce the proteins which the virus needs in order to replicate to billions of new vira. The virus penetrates into the host cell where it liberates its RNA which is a copy of the heritage material, DNA. RNA is like a 'cook book' which contains the recipes of which proteins the virus needs for replication.
The work process of a virus
The cell has ribosomes, a kind of 'molecular motors', which move along the RNA and read the code for the proteins to be produced to fulfill the needs of the living cell. The task of the ribosomes is to read the code of the host cell, but the virus has the special trick that its RNA resembles that of the host cell, and hence, the ribosomes of the host cell will start reading the viral RNA and produce the proteins requested by the virus. In order words, the virus can be viewed as a parasite, exploiting the human cell to live and replicate in.
Viral RNA resembles human RNA, but it has a tendency to curl up into 'pseudoknots', a three dimensional structure. When the ribosome walking along an RNA encounters a pseudoknot it needs to unravel the pseudoknot before it can proceed. Question is, how does it do that? Lene Oddershede at the Niels Bohr Institute, University of Copenhagen has developed optical tweezers which can investigate and manipulate molecules at the nano-meter scale. Using a tightly focussed laserbeam this instrument can grab the ends of the RNA tether and follow the process of how the pseudoknot is mechanically unfolded.
A crucial slip of the cellular motor
In their investigations the researchers use a pseudoknot which is related to bird flu. When the ribosome encounters a pseudoknot it has to unravel the knot before the reading can proceed. During this process the ribosome sometimes slips backwards and, like the letters making up a word, it now reads a new RNA sequence and hence uses another recipe to construct the protein. The researchers have found that the stronger the pseudoknot the more often this backwards slipping happens. The different protein formed is the protein needed by the virus, with possible serious consequences for the hosting organism. This is the manner in which many vira, e.g. HIV, trick the cell into producing something which it never would have done otherwise. Understanding the role of the pseudoknots can be an important step in developing a viral vaccine.
Gertie Skaarup | EurekAlert!
Hunting pathogens at full force
22.03.2017 | Helmholtz-Zentrum für Infektionsforschung
A 155 carat diamond with 92 mm diameter
22.03.2017 | Universität Augsburg
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...
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...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
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...
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...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
22.03.2017 | Materials Sciences
22.03.2017 | Physics and Astronomy
22.03.2017 | Materials Sciences