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."
|Contact: Professor Thomas Carell|