Our understanding of how messenger RNAs are translated into proteins is challenged by new research published today in the Open Access journal Journal of Biology. The study suggests that EF-G, the GTPase that facilitates tRNA translocation in bacteria, enters the ribosome bound to a different guanine nucleotide than previously thought – GDP, not GTP. The ribosome itself then seems to act as the guanine-nucleotide exchange factor, not some as-yet-unidentified factor as previously assumed. This finding questions the prevailing model for RNA translocation.
According to the textbook model EF-G provides the energy needed for the translocation phase of translation by bringing GTP into the ribosome where GTP is subsequently hydrolysed into GDP.
Andrei Zavialov, Vasili Hauryliuk and Måns Ehrenberg from Uppsala University in Sweden first performed an important purification step ensuring that their GTP was not contaminated by GDP (and vice versa), as had been the case with previous studies using these purified components. They next measured the affinity of EF-G for GTP and GDP. Their results strongly suggest that EF-G is bound to GDP in the cytoplasm and that it binds to the pre-translocation complex - composed of the ribosome, tRNA and mRNA strand – as a EF-G-GDP complex. The ribosome itself then seems to act as a GTP exchange factor that swaps GDP for GTP, which results in a modification in the structure of the ribosome. This triggers partial translocation of the mRNA, which is completed after GTP hydrolysis. “Our results suggest that the ribosome plays a previously unidentified dual role of both guanine-nucleotide exchange factor and GTPase-activating protein” explain the authors. EF-G then detaches from the ribosome in its GDP-bound form, ready to be used again by another ribosome.
Juliette Savin | alfa
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences