Advanced X-ray techniques produce insights into bacterial enzymes that convert methane gas into liquid fuel.
Scientists have come up with a unique enzyme structure, produced by metallic bacterial species, which converts greenhouse gases into methanol – a highly versatile liquid fuel and industrial product.
New research, published on Journal of the American Chemical Society, is the first to report the structure of an enzyme, called soluble methane monooxygenase (sMMO), at room temperature in a reduced and oxidized form. This detailed structural information will help researchers design efficient catalysts for the industrial methane process into the process.
“We can unravel the structure of sMMO and see how the environment of the two iron atoms in the active site of its enzymes changes and supports the catalysis of this challenging chemical reaction,” said author Jan Kern, Berkeley Lab bioscientist. The process “involves breaking the carbon-hydrogen bond and oxygen inserts – converting hydrocarbons into alcohols. In addition, our results show the value of using X-ray free electron beam (XFEL) in situations where traditional crystallography is not possible, in this case because the reactive metal enzyme. “
Studying such enzymes in the traditional way X-rays usually give incorrect results due to radiation damage. By using XFEL, researchers can obtain accurate structural information on the two oxidation states.
Bacteria that metabolize methane (methanotrophs) are in the oxygen-rich soil and aquatic environment. In these anaerobic habitats, bacteria play a critical role as carbon recycling; they convert methane (CH4) into more useful molecules that they and other organisms depend on.
References: “XFEL High-Resolution Structure of Methane Solution Monooxygenase Hydroxylase Complex and Regulating Components at Temperature in Two Oxidation States” by Vivek Srinivas, Rahul Banerjee, Hugo Lebrette, Jason C. Jones, Oskar Aurelius, In-Sik Kim Cindy C. Pham, Sheraz Gul, Kyle D. Sutherlin, Asmit Bhowmick, Juliane John, Esra Bozkurt, Thomas Fransson, Pierre Aller, Agata Butryn, Isabel Bogacz, Philipp Simon, Stephen Keable, Alexander Britz, Kensuke Tono, Kyung Sook Kim, Taman Sang- Youn, Sang Jae Lee, Jaehyun Park, Roberto Alonso-Mori, Franklin D. Fuller, Alexander Batyuk, Aaron S. Brewster, Uwe Bergmann, Nicholas K. Sauter, Allen M. Orville, Vittal K. Yachandra, Junko Yano, John D Lipscomb, Jan Kern and Martin Högbom, July 20, 2020, Journal of the American Chemical Society.
DOI: 10.1021 / jacs.0c05613
This research is a collaboration between scientists at Berkeley Lab, University of Minnesota, Stockholm University, SLAC, and Diamond Light Source.