1. Department of Microbiology and Immunology, Institute of Molecular Biology, Jagiellonian University, 31-120 Krakow,1 and
2. Department of Medical Microbiology and Immunology, University of Aarhus, DK-8000 Aarhus, Denmark2;
3. Center of Microbiological Research and Autovaccines, 31-016 Krakow,3Poland;
4. Institut Pasteur Unite Regulation de l'Expression Genetique, 75724 Paris, France4;
5. Department of Genetics, Groningen Sciences and Biotechnology Institute, Haren, The Netherlands5; and
6. Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 306026