About the Authors
Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
Institut für Virologie, Philipps-Universität Marburg, Marburg, 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: SB JAGB. Performed the experiments: TAMB JDR LK SW VK MLP. Analyzed the data: TAMB JDR SW ND JAGB. Wrote the paper: TAMB JDR SW SB JAGB.