1. Archaea Centre; Department of Biology, University of Copenhagen, København; Denmark
2. Structural Biology and NMR Laboratory and The Linderstrøm-Lang Centre for Protein Science, Department of Biology; University of Copenhagen, København; Denmark
3. Department of Pharmacology; University of Copenhagen, København; Denmark
4. State Key Laboratory of Microbial Resources; Institute of Microbiology, Chinese Academy of Sciences; Beijing China