1. Department of Molecular Microbiology, Washington University Medical School, St. Louis, Missouri, USA
2. Department of Molecular and Cellular Biology, University of Guelph, Ontario, Canada
3. Center for Bioinformatics, Faculty of Natural Sciences and Technology, Saarland University, Saarbruecken, Germany
4. Department of Biology, Faculty of Natural Sciences and Technology, Saarland University, Saarbruecken, Germany