We thank the Max Planck Institute for Marine Microbiology and the Max-Planck-Society for continuous support. We thank the SOLEIL and SLS synchrotrons for beam time allocation and the respective beamline staffs of Proxima-1 and X06DA for assistance with data collection, with specific regards to P. Legrand. We also acknowledge C. Probian and R. Appel for their continuous support in the Microbial Metabolism laboratory. We are thankful to R. Amann and R. K. Thauer for their critical views on the manuscript and their stimulating discussions. We thank K. Knittel for her inputs during a regular exchange. We thank A. Teske for organizing the sampling campaign of the Guaymas Basin hydrothermal vents (NSF grant 1357238). Funding:
Additional funds came from the Deutsche Forschungsgemeinschaft funding the Cluster of Excellence “The Ocean Floor—Earth’s Uncharted Interface” (EXC-2077–390741603) at MARUM, University Bremen. S.E. was granted by SNF grant 200021_182369. Author contributions:
C.J.H., O.N.L., G.W., and T.W. designed the research. C.J.H., O.N.L., and G.W. performed cultivation and culture experiments. C.J.H., O.N.L., and T.W. purified and crystallized the proteins. S.E., O.N.L., and T.W. collected x-ray data and built the models. O.N.L. and T.W. analyzed the structures. S.E. and T.W. performed and analyzed the xenon-pressurization experiments. J.K., O.N.L., and T.W. analyzed the F430
cofactor and posttranslational modifications. C.J.H., O.N.L., G.W., and T.W. interpreted the data and wrote the paper, with contributions and final approval of all co-authors. Competing interests:
The authors declare no competing interests. Data and materials availability:
All structures were validated and deposited in the Protein Data Bank (PDB) under the following accession numbers: 7B1S, native ethyl-coenzyme M reductase from Ca.
E. thermophilum; 7B2C, Xenon-pressurized ethyl-coenzyme M reductase from Ca.
E. thermophilum and 7B2H, Xenon-pressurized methyl-coenzyme M reductase from M. marburgensis
. Raw and processed data for x-ray crystallography and mass spectrometry experiments are hosted at Zenodo (35
). All other data are available in the manuscript or the supplementary materials.