About the Authors
Department of Structural Biology, Max-Planck-Institute of Molecular Physiology, Dortmund, Germany
Department of Physics, University of Osnabrück, Osnabrück, Germany
The authors have declared that no competing interests exist.
The author(s) have made the following declarations about their contributions: Conceived and designed the experiments: JPK AW. Performed the experiments: SM SB AK JPK. Analyzed the data: SM SB JPK AW. Contributed reagents/materials/analysis tools: HJS. Wrote the paper: SM SB HJS JPK AW. Performed the protein preparations and biochemical experiments, performed the crystallization experiments, X-ray data analysis, and solving of the X-ray structures: SM. Performed and analyzed the EPR experiments: SB JPK. Designed the mutants: SM AK JPK. Provided the EPR equipment: H-JS. Performed the protein preparations and biochemical experiments: AK.