Researchers of the University of Washington, Seattle, and the Max Planck Institute for Terrestrial Microbiology, Marburg, discovered enzymes and coenzymes in a methylotrophic bacterium which were thought to be unique to methanogenic archaea (Science, vol. 281, 3 July 1998).
Central metabolic pathways involving the oxidation/reduction of carbon compounds consisting of only one carbon atom (C1 transfer pathways) are present in virtually all organisms, where they function to provide C1 intermediates at different oxidation states of use in a variety of biochemical processes.
Methanogenic archaea and methylotrophic bacteria represent two large groups of organisms in nature. They have in common an energy metabolism involving C1 transfer reactions. Methanogens are strictly anaerobic (oxygen-intolerant) microorganisms which belong to the domain of the archaea, one of the three domains of life (archaea, bacteria, eucarya). Their central carbon metabolism involves the conversion of the C1 compound carbon dioxide (CO2) to methane (CH4) in the presence of hydrogen. Methylotrophic bacteria represent a ubiquitious group of aerobic (oxygen-dependent) microorganisms which belong to the domain of the bacteria and grow on methanol (CH3OH), simple methylated compounds or methane under the formation of carbon dioxide.
Both groups of organisms, methanogenic archaea and methylotrophic bacteria, are phylogenetically not related as indicated already. Their energy metabolism centered around C1 compounds was thought to be completely unrelated.
Data are now available which show that the central C1 metabolism of a methylotrophic bacterium involves genes, enzymes and coenzymes with surprisingly high identity to some of those involved in the pathway of methanogenesis. These findings have implications for understanding not only the metabolism of these specific two groups of organisms, but to understanding the evolutionary history of C1 pathways
Contact: Julia Vorholt