1. Microbiologie Moléculaire et Génie des Protéines, Pavillon Charles-Eugène Marchand, Faculté de Médecine, Université Laval, Sainte-Foy, Québec, Canada G1K 7P41;
2. Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, California 931062
3. Department of Microbiology and Infectious Diseases, University of Calgary, Alberta, Canada T2N 4M13; and