The study, co-written by Gustavo Caetano-Anollés, a professor of crop sciences, and postdoctoral researcher Feng-Jie Sun, appears March 7 in PLoS Computational Biology. Caetano-Anollés is an affiliate of the U. of I. Institute for Genomic Biology.
Of the thousands of RNAs so far identified, transfer RNA (tRNA) is the most direct intermediary between genes and proteins. Like many other RNAs (ribonucleic acids), tRNA aids in translating genes into the chains of amino acids that make up proteins. With the help of a highly targeted enzyme, each tRNA molecule recognizes and latches onto a specific amino acid, which it carries into the protein-building machinery. In order to successfully add its amino acid to the end of a growing protein, tRNA must also accurately read a coded segment of messenger RNA, which gives instructions for the exact sequence of amino acids in the protein.
The fact that tRNA is so central to the task of building proteins probably means that it has been around for a long time, Caetano-Anollés said. His inquiry began with a hunch that understanding the structural properties of tRNA would shed light on how organisms and viruses evolved.
“Perhaps in evolution there are things that are so fundamental that they are kept, held onto, for millions or even billions of years,” Caetano-Anollés said. “Those are the fossils, the molecular fossils, that tell us about the past. “Therefore, studying these molecules can address fundamental questions in biology and evolution.”
All tRNAs assemble themselves into a shape that, if flattened, resembles a cloverleaf. The team began by looking for patterns in this cloverleaf structure, using detailed data from hundreds of molecules representing viruses and each of the three superkingdoms of life: archaea, bacteria and eukarya.
The researchers converted all distinguishing features of the individual tRNA cloverleaf structures into coded characters, a process that allowed a computerized search for the most “parsimonious” (that is, the simplest, most probable) tRNA family tree. They conducted the same analysis on the tRNAs of each of the superkingdoms, to see how far these groupings diverged from the overall tree. This comparison allowed them to determine the order in which viruses and each of the superkingdoms diverged.
The new analysis supports an earlier study that suggested that the archaea were the first to arise as an evolutionarily distinguishable group. Archaea are microbes that can survive in boiling acid, near sulfurous ocean vents or in other extreme environments. The earlier study, also led by Caetano-Anollés, analyzed the vast catalog of protein folds – those precisely configured regions in proteins that give them their functionality – as a guidebook to evolutionary history.
“The transfer RNA data matches our earlier data,” Caetano-Anollés said. “This is important because two lines of independent evidence are supporting each other.”
The new analysis also indicates that viruses emerged not long after the archaea, with the superkingdoms eukarya and bacteria following much later – and in that order. This finding may influence the ongoing debate over whether viruses existed prior to, or after, the emergence of living cells, Caetano-Anollés said.
“This supports the idea that viruses arose from the cellular domain,” he said.
Diana Yates | University of Illinois
Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel
Carcinogenic soot particles from GDI engines
24.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
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....
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...
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...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
23.05.2017 | Event News
22.05.2017 | Event News
17.05.2017 | Event News
24.05.2017 | Earth Sciences
24.05.2017 | Life Sciences
24.05.2017 | Life Sciences