In the UniCat Cluster of Excellence (Unifying Concepts in Catalysis) in Berlin, a new concept is being developed by biochemist Nediljko Budisa in collaboration with French biologist Philippe Marlière that aims to equip industrial bacteria for new catalytic functions. They call this new technique „codon emancipation“.
At the same time a genetic firewall is established, making the bacteria dependent on a special growth medium. This means that they cannot survive in a natural set-ting, making the transfer of genes into the environment impossible.
Budisa and Marlière hope to replace old-fashioned natural chemistry with a new type of science. This development is to be achieved through the directed evolution of more natural, faster-growing bacteria in a test tube. “These cells are, in a manner of speaking, in a parallel world,” explains Budisa. They cannot exchange their genetic information with other creatures; they are equipped with a genetic firewall.”
At the start of the process the bacteria will in fact grow very badly in the synthetic growth medium with the non-natural amino acids. But by cultivating them for several generations, they will eventually become „codon emancipated”. „Codon emancipation” offers the possibility of providing living systems with new chemistry. On the one hand, the way to artificial biological diversity is viewed with scepticism in scientific circles. But on the other, if the process is successful then the resulting cells will be enormously useful in industry. For example, new environmentally friendly bio catalysts for manufacturing fuel, new active ingredients for medicinal products and more environmentally friendly biomaterials are just some conceivable uses. At the same time this project provides the scientific community with an opportunity to consider problems and misgivings concerning the biosafety of synthetic organisms and to address these publicly.
The chemically modified bacteria will theoretically be viable for an unlimited period of time in genetic isolation from natural species. As soon as the non-natural amino acids are no longer provided in the growth medium, they will die. The “codon emancipation” therefore constructs a "genetic firewall" against a potential genetic exchange between artificial and natural cells.
Philippe Marlière explains, “We plan to rewrite the entire genomic text of the microbes in the test tubes through cumulative mutations, creating quick-growing cells with permanent evolutionary pressure. To do this, we have developed an automaton, what is known as a “gene machine” over the course of the last ten years.”
These developments are at the forefront of synthetic biology. The work of the renowned Americans Craig Venter and George Church is in contrast more or less within the framework of classic genetic engineering, based as it is on the copying and resynthesising of structures that are present in nature with the help of synthetic DNA oligomers.
Matthias Driess, Chair of the UniCat Cluster of Excellence, is enthusiastic about the prospects for the work based on the joint expertise of Budisa and Marlière. “This will be an excellent reinforcement to the bio part of our Cluster. Philippe is a superb innovator, while Nediljko is an original thinker with a superb intellectual profile and a hard worker who has followed his own original ideas and ambitious targets for decades, without being distracted by the scientific mainstream or the fashions in the German research scene, by which I mean he successfully swims against all the tides. We anticipate not only the development of a unique whole-cell catalyst, but also the development of artificial life forms with functions that have not yet been invented by natural evolution.”
The genetic code and the concept of „codon emancipation“
The genetic code was solved in 1966 and is identical for all living creatures. This means that in every organism, a specific sequence of nucleic acids in the DNA carries the same protein molecule.
The genetic code determines the way in which the sequence of bases adenine (A), cytosine (C), guanine (G) and thymine (T) are translated into protein. Every three bases stand for one amino acid, in a triplet known as a codon. There are only 64 codons that generate 20 amino acids. This means that the majority of amino acids are encoded by several codons.
For example, the amino acid arginine can be represented using the six codons CGG, CGA, CGC, CGU, AGG and AGA. AGG and AGA are used very seldom in bacteria such as Escherichia coli. Thus theoretically, for example, all AGGs in the genetic makeup of a living creature could be allocated a new, non-natural amino acid. The cell is then said to be “codon emancipated”, meaning that the old chemistry has been replaced with new.
The Cluster of Excellence Unifying Concepts in Catalysis (UniCat)
“Unifying Concepts in Catalysis” (UniCat) is the sole Cluster of Excellence researching the economically important field of catalysis. More than 250 chemists, physicists, biologists and engineers from four universities and two Max Planck research institutes from Berlin and Potsdam are involved in this interdisciplinary research network. The Cluster is hosted by the Technische Universität Berlin. UniCat receives funding of approximately 5.6 million Euro each year as part of the Excellence Initiative of the German Research Foundation.For further information, please contact:
References:Hoesl, M. and Budisa, N. (2011). In Vivo Incorporation of Multiple Noncanonical Amino Acids into Proteins. Angew. Chem. Int. Ed. Engl. 50, 2896-2902.
http://onlinelibrary.wiley.com/doi/10.1002/anie.201005680/fullSchmidt, M. (2010), Xenobiology: A new form of life as the ultimate biosafety tool. BioEssays, 32, 322–331
http://onlinelibrary.wiley.com/doi/10.1002/bies.200900147/abstractMarliere P. (2009). The farther, the safer: a manifesto for securely navigating synthetic species away from the old living world. Syst. Synth. Biol. 3, 77-84.
http://www.springerlink.com/content/j504q5032553n326/Budisa, N. (2004). Prolegomena to future experimental efforts on genetic code engineering by expanding its amino acid repertoire. Angew. Chem. Int. Ed. Engl. 43, 6426-6463.
Stefanie Terp | idw
Show me your leaves - Health check for urban trees
12.12.2017 | Gesellschaft für Ökologie e.V.
Liver Cancer: Lipid Synthesis Promotes Tumor Formation
12.12.2017 | Universität Basel
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
12.12.2017 | Physics and Astronomy
12.12.2017 | Earth Sciences
12.12.2017 | Power and Electrical Engineering