The Archaea are single-celled organisms and a domain unto themselves, quite apart from the so called eukaryotes, being bacteria and higher organisms. Many species live under extreme conditions, and carry out unique biochemical processes shared neither with bacteria nor with eukaryotes.
Methanogenic archaeans, for example, can produce methane gas out of carbon dioxide and hydrogen. The underlying chemical reaction, a reduction, involves the cofactor known as F0 or F420 which is the tiny molecule deazaflavin. It has previously been found only in methanogenic bacteria, and has accordingly been considered the signature molecule for those species.
A research group working with Professor Thomas Carell, however, has now shown that this cofactor is also common in eukaryotes, where it performs an entirely different function: deazaflavin is involved in DNA repair processes. (PNAS Early Edition online, 1 July 2009)
Catalysts assist in chemical reactions without undergoing any alteration of their own. In the cells of living organisms, proteins perform this important function. They carry out the metabolism fundamental to all living processes. Proteins are instrumental in cellular respiration, they for instance reduce oxygen to water and oxidize food into carbon dioxide. This releases the energy that makes life possible at all. Proteins cannot perform these functions on their own. They depend on small helper molecules.
Such molecules are stored inside special pockets in the proteins and carry out essential metabolic functions. The living organism itself produces many of these helpers. Others – like vitamins – must be obtained from food. Severe vitamin deficiencies are a harsh reminder of how essential these molecules are.
Methanogenic bacteria have quite an exceptional task to accomplish: They have to produce methane. In terms of chemistry, this is no mean feat. Methane production is currently one of the most hotly pursued goals for the purposes of renewable energy. It is also a serious greenhouse gas.
Enzymatic methane production involves the tiny molecule deazaflavin, known as cofactor F0 or cofactor F420. This cofactor is stored inside special proteins of methanogenic bacteria, and is essential for methane biosynthesis. Cofactor F0/F420 is a small molecule that, until now, has only been found in methanogenic bacteria. It is regarded as the signature molecule for such species.
"We have now shown that this picture is not entirely true," Carell says. "This cofactor is significantly more widespread in the biosphere than previously assumed. Most importantly, it also occurs in higher organisms, the so-called eukaryotes. But in these, it performs a completely different task." As the researchers were able to demonstrate, the cofactor is involved in DNA repair processes. Specifically, repair of UV damage to the DNA molecule.
Plants and many other organisms that are exposed to intense sunlight must cope with an enormous degree of damage to their genes. To repair those mutations, they need the help of complex enzymes. These photolyases in turn require cofactor FAD – aka vitamin B2 – to accomplish this function. It has long been suspected that these crucial enzymes require yet another cofactor to provide the energy that DNA repair requires.
"We have now shown that, in many organisms, this cofactor is F0/F420," Carell reports. "This molecule has been conclusively detected in DNA repair enzymes of Drosophila melanogaster, the fruit fly. Not long ago, another research group even postulated that F0/F420 is co-responsible for DNA repair in plants. Our view of cofactor F420 as a signature molecule for methanogenic species has therefore radically changed: this cofactor is widespread and it is essential for both methane synthesis and for DNA repair."
Professor Thomas Carell is speaker of the "Center for Integrated Protein Science Munich (CiPSM)" center of excellence which supported this research.
Publication: "The archaeal cofactor F0 is a light-harvesting antenna chromophore in eukaryotes", Andreas F. Glas, Melanie J. Maul, Max Cryle, Thomas R. M. Barends, Sabine Schneider, Emine Kaya, Ilme Schlichting, and Thomas CarellContact:
Further reports about: > Cellular Respiration > DNA > DNA repair > Drosophila melanogaster > F0/F420 > Hydrogen > Methane-producing molecule > Protein > Rampant > Rampant helper syndrome > carbon dioxide > chemical process > chemical reaction > dioxide > eukaryotes > living organism > metabolic functions > methane biosynthesis > molecule deazaflavin > repair process > single-celled organism
Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University
Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017
25.04.2017 | Laser Zentrum Hannover e.V.
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
25.04.2017 | Physics and Astronomy
25.04.2017 | Materials Sciences
25.04.2017 | Life Sciences