1. Unité de Biologie Moléculaire du Gène chez les Extrêmophiles, Institut Pasteur, rue Dr. Roux 25, 75724 Paris Cedex 15, France
2. Department of Microbiology, Archaea Centre, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
3. Danish Archaea Centre, Institute of Molecular Biology, Copenhagen University, Sølvgade 83H, DK-1307 Copenhagen, Denmark